The Point · Westport Quay
As of Mon 19 Oct, 17:55
Dry
The water is 1.2 m below the foot of the steps. The tide won't reach the steps again until Wed around 14:31. Low water 19:53.
Depth ±0.4 m: an estimate, not a measurement. Tell us where the water was
Sea level

LW 19:53HW 02:06LW 08:21HW 14:11
17:55
Drag to any time in the next 24 hours. Depth is at the foot of the steps.

Westport tide times

Monday 19 October: High tide at 00:24 (+0.5 m) and 12:43 (+0.8 m), low tide at 06:33 (−0.2 m) and 19:53 (−0.5 m). Neap tides, with a range of only 1.3 m. At the Point, high tide doesn't reach the foot of the steps.

Westport Quay: high and low tide, Mon 19 Oct to Mon 26 Oct. Heights in metres above OD Malin.
DayHigh tideLow tideRange
Mon 19 Octneaps00:24 +0.5
12:43 +0.8
06:33 −0.2
19:53 −0.5
1.3 m
Tue 20 Octneaps02:06 +0.6
14:11 +0.8
08:21 −0.3
21:09 −0.7
1.5 m
Wed 21 Octneaps03:21 +0.8
15:16 +1.0
09:31 −0.5
21:59 −1.0
2.0 m
Thu 22 Octbuilding04:07 +1.0
16:04 +1.3
10:18 −0.8
22:38 −1.3
2.5 m
Fri 23 Octbuilding04:43 +1.3
16:44 +1.5
10:55 −1.1
23:12 −1.6
3.1 m
Sat 24 Octbuilding05:16 +1.6
17:22 +1.8
11:30 −1.4
23:45 −1.8
3.6 m
Sun 25 Octsprings04:50 +1.8
16:59 +2.0
11:04 −1.6
23:19 −2.0
3.9 m
Mon 26 Octsprings · full moon05:24 +2.0
17:38 +2.1
11:39 −1.8
23:55 −2.0
4.1 m

Irish time. Heights are metres above or below OD Malin, the Irish land-survey datum, which sits within a few centimetres of mean sea level here; for heights above chart datum, as on Admiralty charts, add about 2.5 m. Worked out from the Marine Institute's predictions for Roonagh Pier, at the mouth of Clew Bay, shifted to the Quay: high tide about 20 minutes later, low tide about 35 minutes later, from the Admiralty's 1868 Sailing Directions and its modern predictions for Inishgort. No tide gauge has measured the Quay itself. Weather can push the real tide tens of centimetres either way. From Roonagh to the Point · Elsewhere in Clew Bay

Today and the next three days

When is there water at the steps?

Westport Bay is shallow and the shelf in front of the Point dries for most of every tide, so the question is never if but when. Pick what you're after:

0 m1 m2 mwadedipswimHW 00:24LW 06:33HW 12:43LW 19:530003060912151821
Today 17:55: dry at the foot of the steps. Water level −0.32 m OD Malin.

Depth of water at the foot of the steps, from midnight to midnight. Shaded: the times there is at least the depth you picked. Grey bands: night. Tap or drag the chart for any time.

The next four days

What the words mean. Depth of water at the foot of the steps, set against someone 1.72 m tall using standard body proportions1. Wade: 0.3 m or more, up the shins. Dip: 0.7 m or more, thigh-deep; sit down and you're in to the shoulders. Swim: 1 m or more, hip-deep and up, enough for breaststroke with your knees clear of the stones. These are our rules of thumb, not anyone's regulations. Further out from the steps the shelf is a little lower, so there is a bit more water than this.

Finding the steps

Map of the Point and Roman Island from the 2011 LiDAR survey
The west tip of Roman Island, drawn from the 2011 LiDAR survey2 with OpenStreetMap roads3. Pale green: the made ground of the island and the Quay. Sand colours: shore that the tide covers. Blue: under water when the survey was flown. The red dot is the swimming spot. North is up; the bar is 100 m.

Follow the Quay west past the pet-food factory to the free car park at the very tip of Roman Island3. The steps, the shelters and the cold shower are on the south-west side, facing the Reek. Coordinates: 53.8024 N, 9.5603 W.

The small print, once. These are predictions and estimates, not measurements. There's no lifeguard at the Point4. A strong south-westerly or a deep low can lift the tide by a few tens of centimetres above the prediction, and high pressure can hold it down; the bed moves after storms. Have a look before you go in, and watch for a "Do Not Swim" notice from the Council (it has happened here, see below).

Calibration, by the people who swim here

Tell us where the water was

The depth on this page is a sum: predicted tide minus the height of the seabed from a 2011 survey. Nobody has measured it at the steps, and it could be out by 0.4 m either way. Every sighting of where the water actually was, and when, pins it down.

If you were at the Point, tell the page what the water was doing and when. It works out the water level that implies and sets it against the prediction. Do this a few times, at different states of the tide, and you'll know how far to trust the page, or you can let it correct itself. Nothing is sent anywhere: the observations live in this browser only.

    The step heights here come from the page's own picture of the steps (the promenade and the foot from the 2011 survey, the steps spaced evenly between them), so "step 5" is only as good as that picture. "Water's edge at the foot of the steps" is the cleanest thing to report.

    Saved in this browser only, for now; nothing is sent anywhere. Your own sightings can correct the page for you (the switch is under "Your dips"). To pool them, export your log there and pass the file on. A shared sightings store may follow, and the exported files are already in its format.

    Right now

    What it's like down there

    Water
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    Air
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    Wind
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    Chop at the steps
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    Daylight
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    Tide range today
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    Wind and air: Open-Meteo forecast for the Point. Water: the Marine Institute's ocean model, or Météo-France's if that fails. Chop is our own estimate from the wind and the stretch of open water upwind of the steps (how, below). All of it is a forecast for open water, not a reading at the steps.

    Weather data by Open-Meteo.com (CC BY 4.0). Sea temperature: Marine Institute (CC BY 4.0) and Météo-France via Open-Meteo.

    Kept in your browser, not sent anywhere

    Your dips

    Tap I'm in at the top when you're in the water. The page notes the time and its own numbers for that moment: the tide, the depth at the steps, the water temperature, the wind and the chop. If you tell it where the water was on the steps, that sighting also checks the prediction. Everything stays in this browser. Nothing is posted anywhere.

    5°18°water temperature on the day

    To share your sightings, export your log and send the file on, by message or email. Whoever gets it can import it here, and it merges with their own log, skipping duplicates. There's no server: the file only leaves your device if you send it.

    The fortnightly rhythm

    Springs and neaps

    Twice a month the tides get big (springs) and in between they go slack (neaps). Springs come when the sun and moon pull in line, at new and full moon; neaps come with the half moons5. On this coast the biggest tides arrive about a day and a half after the moon, a lag called the age of the tide (we get 33 hours from the Roonagh constants). At the Point that fortnightly swing decides everything: at springs the high water gives you a proper swim off the steps; at neaps it barely reaches them.

    0 m1 m15 Octtoday23 Oct27 Oct31 Oct4 Nov8 Nov
    How deep the day's highest tide gets at the foot of the steps, from a week ago to three weeks ahead. Dashed lines: wade, dip and swim. Circles: new moon (dark) and full moon (pale). Red: today.

    The tides are building: the next springs peak around Wed, 28 Oct, when high water should give about 1.3 m at the foot of the steps. Today's top of the tide: not quite up to the steps.

    Why the Point is a dawn and dusk swim

    On this coast the big spring high waters always come early in the morning and again in the evening, and spring low water falls around the middle of the day. Springs follow new and full moon, when the moon crosses the sky in step with the sun, so they come round at the same clock times every fortnight. The old Admiralty name for it is the "establishment" of the port. At Westport, high water on the day of full and new moon came at 4 h 57 m6: about five o'clock, morning and evening, by the sun. The biggest tides follow a day and a half later, an hour or so later in the day. A botanist on the Clare Island Survey put it plainly in 1912: "Low water at spring-tides is in the middle of the day"7.

    In 2026, by this page's sums, the foot of the steps gets a metre of water or more on 126 tides, about 189 hours in all, every one of them centred between 4:00 and 9:00 in the morning or 17:00 and 22:00 in the evening (Irish time). That is a dawn or dusk swim, or nothing.

    For the diary

    Tide times at the Point

    DayHigh water
    depth at the steps
    Low water
    Today
    Mon, 19 Oct
    00:24 short of the steps
    12:43 short of the steps
    06:33 dry
    19:53 dry
    Tomorrow
    Tue, 20 Oct
    02:06 short of the steps
    14:11 short of the steps
    08:21 dry
    21:09 dry
    Wed
    Wed, 21 Oct
    03:21 short of the steps
    15:16 0.1 m
    09:31 dry
    21:59 dry
    Thu
    Thu, 22 Oct
    04:07 0.1 m
    16:04 0.4 m
    10:18 dry
    22:38 dry
    Fri
    Fri, 23 Oct
    04:43 0.4 m
    16:44 0.6 m
    10:55 dry
    23:12 dry
    Sat
    Sat, 24 Oct
    05:16 0.7 m
    17:22 0.9 m
    11:30 dry
    23:45 dry
    Sun
    Sun, 25 Oct
    04:50 0.9 m
    16:59 1.1 m
    11:04 dry

    Irish time. These are our estimates for the Point, about 20 minutes after Roonagh at high water (see "From Roonagh to the Point"). "Dry" means low water leaves the foot of the steps out of the water.

    The same steps, later

    2050 and 2100

    Use the 2050 and 2100 buttons at the top to see the same tide on the same steps with the sea higher. The rise comes from the IPCC's Sixth Assessment Report, through NASA's Sea Level Projection Tool89. If you click on Westport, the tool gives you the 1° grid cell at 53° N, 10° W, about 94 km south-west of the Point. Its nearest tide gauges, Dublin and Malin Head, are much further away. The numbers include vertical land motion, which here is close to zero (the median is nil, and the likely range is within ±5 cm by 2100). We count the rise from today, 2026.

    2050
    low emissions (SSP1-2.6) +11 cm likely 7–16 cm
    high emissions (SSP5-8.5) +15 cm likely 10–20 cm
    2100
    low emissions (SSP1-2.6) +34 cm likely 20–52 cm
    high emissions (SSP5-8.5) +63 cm likely 46–89 cm
    025050075010001250150017502000hours a year with 1 m+ at the steps220now20263402050low3902050high6902100low12602100high
    Hours a year with a metre or more of water at the foot of the steps, from the same tides on a higher sea. Bars: the median projection. Whiskers: the IPCC's likely range (17th–83rd percentile). Averaged over one 18.6-year lunar cycle of tides.

    Today the foot of the steps gets a metre of water or more for about 220 hours a year. That figure is averaged over a full 18.6-year lunar cycle; 2026 itself is a lean year. By 2050 the figure is about 340 (low emissions) to 390 hours (high). By 2100 it is about 690 (low, likely 470–1020) or 1260 (high, likely 900–1930). More water at the steps also means water further up them. On the tide alone, with no storm, the biggest springs reach the top of the steps not once in most years in 2100 under low emissions, and about 22 times a year under high. Today they don't reach it at all.

    The Quay in the flood maps

    The Office of Public Works maps how far the sea would reach the Quay in a 1-in-10 and a 1-in-200-year storm, today and with a metre more sea: see them on floodinfo.ie10.

    Those maps are about storms, not ordinary tides. The flood study for the Westport plan says tidal flooding "has only impacted the Westport Quay area". It names "Properties along Rossbeg, Harbour View and The Point" as prone to it, says flooding at the Quay "can be as frequent as 1 in 2 years", and gives the highest event on record as 2.75 m OD, on 15 December 201211. For planning, the OPW adds 0.5 m (mid-range) or 1.0 m (high-end) of sea level over a 100-year horizon11. A 2019 planning file on Roman Island used a 1-in-200-year flood level of 3.61 m OD12.

    What this leaves out: tides themselves change a little as the sea deepens; the bed at the steps will move; storms and surges come on top; and the steps may well be rebuilt long before 2100. These are the same tides on a higher sea, nothing more.

    The workings

    How it's worked out, and what we don't know

    Everything above is a sum: water level minus the height of the seabed at the foot of the steps. Both halves have to be on the same vertical datum, and neither is measured at the Point itself. Here is how each half is done, where it could be wrong, and how to tell us.

    How deep is it at the steps, really?

    We put both halves of the sum on OD Malin, the Irish land-survey datum: mean sea level at Malin Head, 1960–6913. It is what the LiDAR uses, and it doesn't care about tides.

    The seabed at the foot of the steps

    The Office of Public Works flew the Westport shore with LiDAR in 2011 (Fugro, 2 m grid, stated accuracy within ±0.2 m)2. At the swimming area the promenade sits at about +2.9 m. The slope drops about 2 m over 8–10 m to the foreshore, which is at +0.8 to +0.95 m at the swimming spot. A shelf of +0.6 to +0.9 m then runs out for some 30 m. LiDAR can't see through water, but when the plane went over, the sea was at about +0.15 m: all across that survey square, the measured ground stops at +0.1 to +0.2 m (our reading of the data). So the shelf was dry and got measured. Further out the bed falls away. The Admiralty chart marks a drying height of 1.4 m "just west of the Point of Roman Island", as quoted in the Council's 2017 slipway report14. That is roughly −1.1 m OD Malin, if chart datum here lies about 2.6 m below mean sea level, which is the gap in the Admiralty's predictions for Inishgort15.

    The page uses +0.9 m for the foot of the steps, and 0.6–1.1 m as the honest range. Two caveats. The survey is from 2011, and the steps were built some time before April 2021 (see below), so their foot may not sit exactly on the old beach. And storms shift stones and sand. If the bottom step sits a step or two below the old beach, you have 20–40 cm more water than we say. If weed and gravel have built up, you have less.

    −3 m−2 m−1 m0 m+1 m+2 m+3 m+4 mm OD Malin+2.90 promenade at the stepsOPW LiDAR 2011+2.75 highest water on record, Dec 2012flood study (with surge)+1.92 mean high water springsthe Point, this page+0.90 foot of the steps (foreshore)LiDAR; could be 0.6–1.1+0.88 mean high water neaps+0.06 mean sea levelMI gauges around Clew Bay−0.76 mean low water neaps−1.14 chart drying height 1.4 mjust west of the Point−1.80 mean low water springs−1.96 Roonagh LAT (its own datum)not used, see below−2.54 chart datum, approx.Admiralty, Inishgort gap
    Every level on this page on one scale, in metres OD Malin. The blue band is the Point's range from mean low water springs to mean high water springs. Dashed lines are other people's datums, explained below.

    Mean sea level, and the Roonagh puzzle

    Tide predictions give heights above a local "lowest astronomical tide", and every gauge's LAT is its own. To get from tide heights to OD Malin, we only need to know where mean sea level sits on OD Malin. The Marine Institute's own gauges either side of Clew Bay agree closely: Galway +0.03 m, Inishmore +0.05 m, Ballyglass +0.07 m, Sligo +0.08 m16. We use +0.06 m.

    The Roonagh gauge, the one the tide comes from, reports its own mean sea level at +0.376 m, with its LAT at −1.955 m17. That is about 0.3 m above every neighbour, and the Marine Institute calls Roonagh "one of the most challenging sites of the entire collection to measure sea level". It also warns that "unresolved offset issues" are possible across the network. So we don't use Roonagh's datum, only the shape and timing of its tide. If Roonagh's figure turns out to be the right one, every depth on this page is about 0.3 m too low, and there'd be more water than we say. INFOMAR's charts use yet another LAT, from the UK Hydrographic Office's VORF model18. Comparing INFOMAR's land heights with the OPW survey, that LAT comes out about 2.6–2.8 m below OD Malin around Westport (our comparison of the two surveys).

    From Roonagh to the Point

    There is no tide gauge in Westport Bay and no official prediction for Westport. The Marine Institute predicts 38 places around Ireland. The nearest is the gauge on Roonagh pier, at the mouth of Clew Bay, 23 km west of the Point19. The tide takes time to work its way in past the islands and up the channel, so we shift each Roonagh high and low water to the Point. This is the old secondary-port method sailors use, with Roonagh's own curve filling in between. What we have to go on:

    Inishgort
    The lighthouse island about 8 km west-north-west of the Point. In the UK Hydrographic Office's Admiralty predictions, it runs 22 min behind Roonah Quay at high water and 34 min behind at low water, with the same range to within 0.1 m. That is our comparison for 17–24 Oct 202615.
    1868
    The Admiralty Sailing Directions: high water at full and change at 4 h 38 m at Clare Island and at 4 h 57 m at Westport, so 19 min later. Springs rise 12¼ ft at Clare Island and 12¾ ft at Westport; neaps rise 9½ ft at both6.
    1837 / 1912
    Lewis has spring tides rising 14 ft at the quays20. A botanist on the Clare Island Survey gives "about 15 feet" of spring rise and fall at Westport Quay, and adds that "On Clare Island the range is, if anything, greater"7.
    2016
    The Council's engineers drew the new slipway and pontoon with tide levels "From Admiralty Tide Tables For Inishgort": MHWS +1.8, MHWN +0.8, MLWN −0.8 and MLWS −1.8 m OD Malin21. One sheet of the same set says +2.3 m for MHWS.

    So the page puts high water 20 min and low water 35 min after Roonagh. Spring high waters are 10 cm higher than Roonagh's and spring lows 10 cm lower, which follows the 1868 half-foot; neaps are the same as Roonagh's. That gives the Point a mean high water springs of +1.9 m and a mean high water neaps of +0.9 m OD Malin. These are close to the 2016 drawing, and they are why the foot of the steps sits right at neap high water.

    This is the biggest uncertainty on the page, along with the seabed. Twenty minutes either way would surprise nobody, nor would 20 cm. The check below is there to sort it out.

    The tide model in this page

    The Marine Institute publishes 5-minute predictions for Roonagh for 2026 to 2028 (CC BY 4.0). Its predictions come from harmonic analysis of the gauge record22. Rather than ask their server every time someone opens this page, we fitted 54 tidal constituents (M2, S2, N2, K1, O1 and the rest, down to the shallow-water M4, MS4 and M6) to all three years. Your phone then works the tide out itself. It applies the standard 18.6-year nodal corrections, so it works with no signal at the Quay and keeps going past 2028.

    How good is it? Fitted on 2026 alone and checked against the Marine Institute's own 2028 predictions, it is within 1.8 cm on average (root mean square), 6 cm at worst, and gets high and low water to within about 2 minutes. The Marine Institute's series only comes in 5-minute steps, so you can't check the times any closer than that.

    The constants give Roonagh a mean level of 2.48 m above its LAT. Mean high water springs is 4.24 m, high water neaps 3.30 m, low water neaps 1.66 m and low water springs 0.72 m. The highest predicted tide from 2026 to 2044 is 4.88 m. The lowest comes out at 0.00 m, which is what LAT means, so the nodal corrections are behaving.

    The springs come about 33 hours after new and full moon here. That is the "age of the tide", worked out from the gap between the S2 and M2 phases.

    This is the astronomical tide only. Weather is not in it. A deep low or a south-westerly gale can add tens of centimetres, and a big high can take some off. The highest water on record at the Quay was 2.75 m OD on 15 December 2012, according to the flood study for the Westport Local Area Plan11, just a quarter of a metre below the promenade.

    The steps, the shelters and the shower

    It didn't come in one go, and we never found drawings for the steps themselves. What the record shows:

    2010
    The town plan for 2010–16 set the aim to "create a bathing area at Roman Island with associated facilities"23.
    Apr 2021
    The steps were there by then. The Westport Tourism Organisation told the Council: "The concrete steps at the Point cater to the brave sea swimmers who are growing in number every week. We recommend a lifeguard in July & August"24. Another submission asked for "sheltered changing and rest areas for swimmers at the point"25.
    Summer 2021
    The TidyTowns judge: "The work at Roman Island appears to be very well executed and is I am sure greatly appreciated by all the hardy sea swimmers"26.
    2022
    TidyTowns again: "the Point Swimming Area for the hardy open water swimmers with steps, picnic benches, toilet and even a mobile sauna"27. In December, Irish Water quoted €37,000 for a cold shower: €32,000 for the connection, 240 m of pipe, and €5,000 for the shower28.
    2023
    €60,000 came from the Department of Rural and Community Development's Community Recognition Fund for "Installation of Amenity Facilities at the Point, Quay, Westport"29. In August the Council put out a brief for artists to paint two precast concrete shelters for swimmers, each 4.7 m long, 1.4 m deep and 2.24 m high30.
    2024
    In February, "Shelters at The Point are nearly completed"31. On 18 September the Council announced: "New shelters and an outdoor shower were recently constructed and are now operating"32. The TidyTowns judges liked "the covered seats, the low sea washed stones as a barrier to the fall from the quay and the steps leading down to the sea floor"33.
    Now
    "The Point is now used all year round for summer and winter swimming," Cllr Peter Flynn told a Council committee this month34. The 2024–30 town plan wants "a lido pool and disabled access beside the existing entrance steps"35. A €500,000 bid for the Quay and Roman Island failed to get funding in January36. In August the Council put €100,000 into a masterplan for the Roman Island end of the Quay37.

    All of this was done by Mayo County Council; the TidyTowns reports credit "Mayo Co Co" by name. The 2019 slipway and pontoon, €225,000 of Department funding, were a separate job, further east on the river channel38.

    Not found: when the steps and the stone edge were built, what they cost, and any drawing with their levels (no Part 8 or foreshore licence for them turned up). So the picture at the top draws ten even steps between the 2011 survey's ground levels. If you know the year, or have counted the steps, that's the kind of thing this page wants to be corrected on.

    Roman Island and the Quay

    Where the name comes from: unknown. The name turns up in town plans, planning files and the National Inventory of Architectural Heritage, but none of them explains it. The Schools' Collection has nothing on it, and logainm.ie's page was closed to our searches. Ask around.

    Roman Island is "a low drumlin … connected by a causeway to the mainland at Westport Quay". It went from "pleasure gardens in 1840s" to industry and the port, according to an architect's statement summarised in the 2019 planning appeal12. A local-history blog reads the early Ordnance Survey map as showing a true island, joined by the causeway before 1913. It says the 25-inch map shows a Bath Hotel and a bathing house with hot salt-water seaweed baths39; the 2005 town plan mentions "the former site of the Old Bath Hotel"40. A six-storey shipping store went up on the island in 1908 to a design by William Friel. It was demolished in 201541. The fish-feed plant on the island reopened as Irish Pet Foods in November 201642.

    The Quay itself is listed as "built 1780; extant 1818 … Undergoing reconstruction, 1837"43. Lewis, in 1837, has the port founded in 1780 for the herring fishery, and adds: "The quays are now being extended, and when completed will be nearly a mile in length"20. The big stores along it were built between the Act of Union and 1840, according to a 1930s Schools' Collection account44. By the mid-20th century the port was in decline45.

    People swam here long before the steps. Mayo County Library's Lyons collection includes "Young swimmers at the Point Roman Island Westport. Taken in 1950s", "Ladies Swimming Club at Westport Quay, 1955" and "Old Bath Hotel & Roman Island, Westport, 1972"46. Football was "regularly played at The Point". In one 1960s game Mickey Guthrie, "a noted swimmer and lifesaver, dived into the sea" after the ball47.

    Is it an official bathing water?

    No. The Point is not one of the 153 identified bathing waters that the EPA classified in 2025. Mayo has 16 of them and none is in Westport48, and it isn't among the 240 places on beaches.ie either49. The nearest identified water is Bertra, 6.8 km west, rated Excellent from 2022 to 202548.

    The Council does treat it as a bathing place, though. It names "The Point, Westport" among its bathing areas when it warns about water quality50. It has put up prior-warning notices before heavy rain, and it has issued Do Not Swim notices here:

    • June 2022, "due to elevated levels of bacteria"51
    • November 2022, after "an incident with the Quay Road wastewater pump station"52
    • August 202353
    • late August and September 2024, "due to deterioration in bathing water quality"54

    We found no sampling results published for the Point. After heavy rain, check beaches.ie and mayo.ie before you go in. In 2026 the Council ran its yearly call for nominations for new bathing waters; it closed on 25 September55.

    There is no lifeguard. The Point isn't on the Council's list of lifeguarded beaches4. In June 2017 a man drowned while swimming with others at the Point56.

    Water temperature: whose number?

    Nobody measures the water at the steps, so the number on the card is a model's.

    • Marine Institute NE Atlantic model (ROMS, about 1.4 km grid), sea-surface temperature, hourly57. The model has no water cells inside Westport Bay. The nearest one is at 53.806 N, 9.631 W, 4.7 km west of the Point, out past the channel.
    • Météo-France sea-surface temperature through Open-Meteo's marine service (0.08°, about 8 km)58. Its nearest cell is about 9 km north-west of the Point. We use it only if the Marine Institute doesn't answer, and show it alongside when both do.

    For a feel of the seasons, the Marine Institute's coastal temperature network had a logger 1 m down at Inishoo Bay, 9 km up the bay, from 2005 to 200959. Its monthly means:

    5°10°15°5.6J5.3F5.8M8.0A10.5M13.6J14.9J15.9A14.8S11.1O7.8N6.5D
    Monthly mean water temperature 1 m down at Inishoo Bay, 2005–09 (Marine Institute). Red: this month.

    The shelf at the steps is only a metre or two deep when it's covered, and it has been lying in the sun or the frost a few hours before. So the water at the steps follows the weather more than the bay does: warmer than the model on a sunny summer afternoon on the flood, colder on a frosty winter morning. We round to the half degree and wouldn't bet on the half.

    Chop: which winds reach the steps

    Chop in a bay this sheltered is wind waves, made on the spot. Ocean swell doesn't get in past the islands. How big they get depends on the wind speed and on the fetch: the stretch of open water upwind of the steps. We measured the fetch from the swimming spot every 5° using OpenStreetMap's coastline3, averaged over ±15°. At lower tides we also stop it where INFOMAR's survey has a bank above the water18.

    100 m1 km5 kmNESW
    How far the wind can blow over water before it reaches the steps, by the direction it comes from, at a typical swimming tide (log scale). Westerlies get 2–4 km of water, south-westerlies a few hundred metres to 2 km; north-west round to east are off the land.

    The wave height is the US Army Corps of Engineers' shallow-water forecasting formula from the Shore Protection Manual (1984)60. It takes the forecast wind at 10 m from Open-Meteo61, the fetch and the mean depth along it. We cap the result where the water at the steps is too shallow to hold a bigger wave. Words for the significant wave height: under 4 cm flat calm, under 10 cm ripples, under 20 cm light chop, under 35 cm choppy, under 55 cm rough, then very rough. It assumes a steady wind that has been blowing for a while. Gusts, squalls and the odd boat wake are not in it.

    Sources and licences
    1. R. Drillis and R. Contini (1966), body segment lengths as fractions of height, as reproduced in D. A. Winter, Biomechanics and Motor Control of Human Movement (fig. 4.1): ankle 0.039, knee 0.285, hip 0.530, elbow 0.630, chest 0.720, shoulder 0.818, chin 0.870, eye 0.936.
    2. Office of Public Works LiDAR, 2011, tile OPW_189 (2 m DTM and DSM, surveyed by Fugro, "RMS error within +/-200mm"), from Geological Survey Ireland's open topographic data. Contains Irish Public Sector Data (Geological Survey Ireland & the Office of Public Works) licensed under CC BY 4.0. gsi.geodata.gov.ie/downloads/LiDAR/OPW_NASC/OPW_189.zip
    3. © OpenStreetMap contributors, ODbL: the Point swimming area (node 9996872068), shower, shelters, slipways and coastline. www.openstreetmap.org/node/9996872068
    4. Connacht Telegraph, "Council confirms list of Mayo beaches lifeguarded this weekend", 20 Jun 2026. www.con-telegraph.ie/2026/06/20/council-confirms-list-of-mayo-beaches-lifeguarded-this-weekend
    5. NOAA Ocean Service, "What are spring and neap tides?" oceanservice.noaa.gov/facts/springtide.html
    6. Admiralty, Sailing Directions for the West Coast of Ireland, Part II (1868), p. 138: "It is high water on full and change at Clare island at 4 h. 38 m. Springs rise 12¼ feet; neaps, 9½ feet. At Westport, at 4 h. 57 m. Springs rise 12¾ feet; neaps, 9½ feet." archive.org/details/sailingdirectio00deptgoog
    7. A. D. Cotton, "Marine Algae", Clare Island Survey part 15, Proc. Royal Irish Academy 31 (1912): "At Westport Quay the rise and fall during spring-tides is about 15 feet". archive.org/details/clareislandsurve00prae
    8. NASA Sea Level Change Team, Sea Level Projection Tool (IPCC AR6), grid cell 53° N, 10° W: total relative sea-level change against 1995–2014, medium confidence, SSP1-2.6 and SSP5-8.5 (median and 17–83% likely range), including vertical land motion. sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool?lat=53&lon=-10&data_layer=scenario
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    10. Office of Public Works, CFRAM Programme (Western CFRAM study), coastal flood maps for Westport Quay: 10% and 0.5% AEP today, and 0.5% AEP in the High-End Future Scenario. CC BY-NC-ND 4.0, so linked here rather than reproduced. www.floodinfo.ie/map/floodmaps
    11. JBA Consulting for Mayo County Council, Draft Westport Local Area Plan, Strategic Flood Risk Assessment (Sept 2023): "Westport Quay 15/12/2012 High tide and storm surge – highest event on record (2.75mOD)". consult.mayo.ie/en/system/files/materials/4193/Draft%20Westport%20LAP%20-%20SFRA.pdf
    12. An Bord Pleanála, inspector's report, case 302783 (Roman Island, decided 27 Sep 2019). www.pleanala.ie/anbordpleanala/media/abp/cases/reports/302/r302783.pdf
    13. NERC Vocabulary Server, L11 "Malin OD": "Mean sea level at Portmoor Pier, Malin Head averaged between 1960 and 1969". vocab.nerc.ac.uk/collection/L11/current/D24
    14. Malachy Walsh and Partners, Westport Slipway and Pontoon, report 17068-6002-A (July 2017), pp. 18–19: "Admiralty Chart 2057 has a drying-out height marked of 1.4m, just west of the Point of Roman Island." assets.gov.ie/static/documents/mayo-county-council-westport-harbour-proposed-new-slipway-and-pontoon-771-mb.pdf
    15. UK Hydrographic Office, ADMIRALTY EasyTide predictions for Inishgort (0697) and Roonah Quay (0700), 17–24 Oct 2026 (Crown copyright); compared with this page's Roonagh model. Used only for time and height differences. easytide.admiralty.co.uk
    16. Marine Institute gauge metadata on data.gov.ie, mean sea level relative to OD Malin: Galway +0.029 m, Inishmore +0.045 m, Ballyglass +0.066 m, Sligo +0.081 m (search "Irish National Tide Gauge Network"). data.gov.ie/dataset?q=Irish+National+Tide+Gauge+Network
    17. Marine Institute, Irish National Tide Gauge Network 12: Roonagh Pier (installed 2016): MSL +0.376 m, LAT −1.955 m relative to OD Malin; mean spring range 3.797 m; "one of the most challenging sites". data.gov.ie record, modified 18 Oct 2026. data.gov.ie/dataset/irish-national-tide-gauge-network-intgn-12-roonagh-pier-tide-guage-co-mayo-ireland-2016-present
    18. INFOMAR (Geological Survey Ireland & Marine Institute), Bathymetry 10 m inshore grid, depths relative to LAT; datum method (UKHO VORF). Contains Irish Public Sector Data licensed under CC BY 4.0. spatial.marine.ie/arcgis/rest/services/test/bathymetry10mCoverage/ImageServer; infomar.ie/surveys/equipment/geodesy-datum-tide
    19. Marine Institute, tide predictions (ERDDAP dataset IMI-TidePrediction), Roonagh, 2026–2028, 5-minute values; station list. CC BY 4.0. erddap.marine.ie/erddap/tabledap/IMI-TidePrediction.html
    20. Samuel Lewis, A Topographical Dictionary of Ireland (1837), "Westport": "spring tides rise to the height of 14 and neap to 8 feet"; "The quays are now being extended" (online transcriptions). www.melocki.org.uk/lewis/Ireland/i03900.txt; peterspioneers.com/Westport.htm
    21. Malachy Walsh and Partners for Mayo County Council, Westport slipway and pontoon, drawings 17068-5002 rev C ("Tide Data From Admiralty Tide Tables For Inishgort (ODM): +1.8 MHWS, +0.8 MHWN, −0.8 MLWN, −1.8 MLWS") and 17068-1002 rev C (30 May 2016), foreshore application. www.gov.ie/en/department-of-housing-local-government-and-heritage/publications/mayo-county-council-westport-harbour
    22. Marine Institute, "Tidal predictions": "derived from harmonic analysis of data measured at the tide gauges around the Irish coast". www.marine.ie/site-area/data-services/marine-forecasts/tidal-predictions
    23. Mayo County Council, Westport Town and Environs Development Plan 2010–2016, objective OO-07: "create a bathing area at Roman Island with associated facilities". www.mayo.ie/getmedia/04793fb3-d1e8-4e0d-89e4-78957c4e998b/Westport-2010-2016.pdf
    24. Westport Tourism Organisation, submission MYO-C16-28 to the Westport plan consultation, 29 Apr 2021. consult.mayo.ie/en/submission/myo-c16-28
    25. WEST, submission to the Westport LAP pre-draft consultation, 29 Apr 2021. consult.mayo.ie/en/system/files/materials/581/3395/WEST%20Westport%20LAP%20Draft%20submission%2029.04_.pdf
    26. SuperValu TidyTowns adjudication report, Westport, 2021. www.tidytowns.ie/u_reports/2021/mayo/2021-County-Mayo-Westport-366.pdf
    27. TidyTowns adjudication report, Westport, 2022. www.tidytowns.ie/u_reports/2022/mayo/2022-Mayo-Westport-366.pdf
    28. Connacht Telegraph, "€37,000 quote for shower at popular Mayo swimming spot", 29 Dec 2022. www.con-telegraph.ie/2022/12/29/e37000-quote-for-shower-at-popular-mayo-swimming-spot
    29. Department of Rural and Community Development, Community Recognition Fund 2023, successful projects (17 May 2023): "Installation of Amenity Facilities at the Point, Quay, Westport €60,000". assets.gov.ie/257760/df6eb197-ba64-40bb-94da-54bc97f48026.pdf
    30. Mayo County Council, Westport Public Art Project Brief, Aug 2023, project 3, "Concrete shelters at 'The Point' swimming area" (location 53.802523, −9.560275). www.mayo.ie/getmedia/281940ec-6b31-4735-afb0-085865c771be/Westport-Public-Art-Project-Brief-August-2023.pdf
    31. Connacht Telegraph, "Master plan for Westport's Roman Island", 2 Feb 2024. www.con-telegraph.ie/2024/02/02/master-plan-for-westports-roman-island
    32. Western People, "Mayo attraction to benefit from new shelters and shower", 20 Sep 2024, quoting Mayo County Council, 18 Sep 2024. www.westernpeople.ie/news/mayo-attraction-to-benefit-from-new-shelters-and-shower_arid-32274.html
    33. TidyTowns adjudication report, Westport, 2024. www.tidytowns.ie/u_reports/2024/mayo/2024-Mayo-Westport-366.pdf
    34. Western People, "Swimmers raise complaints about dogs entering water at popular facility", 15 Oct 2026. www.westernpeople.ie/news/swimmers-raise-complaints-about-dogs-entering-water-at-popular-facility_arid-20330791.html
    35. Mayo County Council, Westport Local Area Plan 2024–2030, p. 56 and objective HSCO 16; Map 5.3 (Roman Island masterplan outline). mayo.ie/getmedia/8d3ff0c0-df51-485b-9718-76b494dd7edd/Westport-Local-Area-Plan-2024-2030.pdf
    36. Connacht Telegraph, "Review of west Mayo quay project rejected for funding", 28 Jan 2026. www.con-telegraph.ie/2026/01/28/review-of-west-mayo-quay-project-rejected-for-funding
    37. Connacht Telegraph, "Funding for master plan to transform Mayo quay area", 7 Aug 2026; Western People, 11 Aug 2026. www.con-telegraph.ie/2026/08/07/funding-for-master-plan-to-transform-mayo-quay-area
    38. Connacht Telegraph, "€225,000 for Westport harbour projects", 31 Mar 2019, and "New facility built at busy Mayo seafront location", 3 Dec 2019. www.con-telegraph.ie/2019/03/31/e225000-for-westport-harbour-projects
    39. "Island 413: Roman Island, Westport", A Lifetime of Islands blog, 28 Jun 2018 (a personal blog reading the historic OS maps). alifetimeofislands.blogspot.com/2018/06/island-413-roman-island-westport-county.html
    40. Mayo County Council, Westport Local Area Plan 2005–2011 ("the former site of the Old Bath Hotel"). www.mayo.ie/getmedia/b0f33324-ffa6-4dc5-8a02-a779721bbb4a/Westport-05-11.pdf
    41. National Inventory of Architectural Heritage, reg. 31308726, Roman Island, Westport Quay: shipping store, "built 1908", William Friel, "[Demolished 2015]". www.buildingsofireland.ie/buildings-search/building/31308726/roman-island-westport-quay-mayo
    42. Connacht Telegraph, "New Mayo pet food manufacturing plant opens", 25 Nov 2016. www.con-telegraph.ie/2016/11/25/new-mayo-pet-food-manufacturing-plant-opens
    43. National Inventory of Architectural Heritage, reg. 31211020, quay, Cloonmonad: "built 1780; extant 1818 … Undergoing reconstruction, 1837". www.buildingsofireland.ie/buildings-search/building/31211020/cloonmonad-westport-quay-mayo
    44. National Folklore Collection, Schools' Collection (1930s), Westport. www.duchas.ie/en/cbes/4428017/4368518/4471902
    45. Connacht Telegraph, "Mayo ports, whaling stations and maritime activities", 18 Jul 2026 (citing Rosa Meehan, 2003). www.con-telegraph.ie/2026/07/18/mayo-ports-whaling-stations-and-maritime-activities
    46. Mayo County Library, Lyons Photographic Collection, "Westport" album index (archived copy, Dec 2023). web.archive.org/web/20231210193121/https://library.mayo.ie/media/Lyons%20Collection/Lyons%20Photographic%20Collection/album/Mayo%20places/Westport/Westport/index.html
    47. Connacht Telegraph, "Westport Quay: a bit of God's heaven", 21 Nov 2021. www.con-telegraph.ie/2021/11/21/westport-quay-a-bit-of-gods-heaven
    48. EPA, Table of Identified Bathing Waters and classifications 2022–2025 (beaches.ie). www.beaches.ie/wp-content/uploads/2026/05/Table-of-Identified-Bathing-Waters-Classifications-2022-to-2025_update-2.pdf
    49. beaches.ie site list (API), 240 locations, fetched 19 Oct 2026. api.beaches.ie/odata/beaches
    50. Connacht Telegraph, "Mayo County Council issues warning over bathing water quality at popular spots", 6 Jun 2025. www.con-telegraph.ie/2025/06/06/mayo-county-council-issues-warning-over-bathing-water-quality-at-popular-spots
    51. Midwest Radio, "Swimming banned at popular Westport location", 15 Jun 2022 (archived copy). web.archive.org/web/20221129150508/https://www.midwestradio.ie/index.php/news/58220-swimming-banned-at-popular-westport-location
    52. Connacht Telegraph, "Do Not Swim notice at west Mayo bathing spot", 4 Nov 2022. www.con-telegraph.ie/2022/11/04/do-not-swim-notice-at-west-mayo-bathing-spot
    53. Midwest Radio, "Two Do Not Swim notices issued for bathing waters in the county", 2 Aug 2023 (archived copy). web.archive.org/web/20230802192600/https://midwestradio.ie/index.php/news/69172-two-do-not-swim-notices-issued-for-bathing-waters-in-the-county
    54. Connacht Telegraph, 29 Aug 2024 and 13 Sep 2024; Western People, Sep 2024 ("due to deterioration in bathing water quality"). www.con-telegraph.ie/2024/09/13/two-do-not-swim-notices-lifted-at-mayo-beaches; www.westernpeople.ie/news/alert-warning-issued-for-popular-mayo-public-area_arid-31337.html
    55. Mayo County Council, "Bathing water identification 2026". www.mayo.ie/news/bathing-water-identification-2026
    56. Irish Times, "Man drowns while swimming in sea at Westport", 9 Jun 2017. www.irishtimes.com/news/ireland/irish-news/man-drowns-while-swimming-in-sea-at-westport-1.3114429
    57. Marine Institute, Northeast Atlantic ROMS model (ERDDAP IMI_NEATL), sea-surface temperature, 0.0125° grid. CC BY 4.0. erddap.marine.ie/erddap/griddap/IMI_NEATL.html
    58. Open-Meteo Marine API, sea-surface temperature from Météo-France (0.08°). CC BY 4.0. open-meteo.com/en/docs/marine-weather-api
    59. Marine Institute, Irish Coastal Temperature Network (ERDDAP ICTempNetwork): Inishoo Bay, 1 m, 2005–2009; Curraun 2004–2025. CC BY 4.0. erddap.marine.ie/erddap/tabledap/ICTempNetwork.html
    60. US Army Corps of Engineers, Shore Protection Manual (1984), vol. 1, ch. 3: shallow-water wave forecasting equations and the wind-stress factor UA = 0.71 U1.23.
    61. Open-Meteo forecast API (best-match models), wind, air temperature, rain, cloud. CC BY 4.0. open-meteo.com/en/docs
    62. Skyline of Croagh Patrick from Westport Quay, computed for the Croagh Patrick page from AWS Terrain Tiles / EU-DEM ("produced using Copernicus data and information funded by the European Union").