All swimming spots › Dorset, England
Can I swim at Portland Harbour Sandsfoot Castle?
Dorset, England · Coastal
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Before you get in
A red flag means do not go in, whatever this page says.
If you get into trouble, float on your back until the cold shock passes. Full advice below.
In an emergency call 999 and ask for the Coastguard, or 112 in the Republic of Ireland.
Water quality today
The last fortnight
What this verdict covers
Independent site, not an official one. This verdict is about water quality. It does not tell you whether the water is safe to get into today.
How it has been rated
The annual classification for 2021 to 2025. Each one is calculated from samples taken over up to four bathing seasons, so these overlap and none of them describes today.
Every sample, 2023 to 2026
45 samples, 2023 to 2026. The highest E. coli count in them was 130 per 100ml, on 28 May 2024; the standard for Excellent is 250 or below and for Good 500 or below.
One bar for each sample, oldest on the left. The taller the bar, the more E. coli that bottle held.
The scale is the same on every beach on this site, which is why a clean beach looks flat — the bars are measured against the standard rather than against that beach’s own worst day. Hover or tap a bar for that day’s figures. A single count over a line is not a failed beach. The classification is worked out as the 90th and 95th percentile of four years of samples, so one bad morning does not decide it — and one good morning does not either.
What these bacteria mean for you
Neither one is what makes people ill by itself. They are markers: they live in the gut, so finding them means sewage or animal waste has reached the water, and whatever else came with it is likely there too.
The usual way to catch something is swallowing the water, and the usual result is a stomach upset. Ear, eye, chest and skin infections are the other common ones. Putting your head under and swimming with an open cut both raise the odds.
The riskiest time is the day or two after heavy rain, when storm overflows discharge and rain washes off farmland — including at beaches rated Excellent for the rest of the season. That is the whole reason this page shows you rainfall and discharges alongside the grade.
Portland Harbour Sandsfoot Castle was rated Excellent for 2025, the highest of the four grades in the Bathing Water Regulations. That grade comes from bacterial samples taken over several seasons, so it describes the beach's record rather than the water on any given day.
The Environment Agency issues a pollution risk forecast each morning during the bathing season for nearly every bathing water in England, and the water company publishes the status of its storm overflows every few minutes.
The regulator records this as a bathing water whose quality can be affected by heavy rain, which is why rainfall in the last 24 hours is shown above.
The rest of its file
What the regulator holds for this place. None of it describes the water today.
- Water
- Coastal
- Area
- Dorset, England
- Monitored outfalls within 5km
- 30 (nearest 0.2km)
- Affected by heavy rain
- Yes, per the regulator
Sea, wind, tide and weather
The sea and the weather here today and for the week ahead. Not the water quality verdict above.
Today
Rain, the week behind and ahead
The weather for the week ahead
Where it is, and what discharges near it
Directions to this bathing water
That is the Environment Agency’s sampling point, which is at the water rather than at a car park. Your maps app will take you to the nearest road it can reach.
The nearest mapped car park is about 460m away in a straight line. That is not a walking distance: OpenStreetMap knows where the car park is and nothing about the path, which may be longer, steeper or not there at all. It is tagged as private, as the mappers wrote it.
What is mapped at this beach
- Toilets about 260m away
- Sandsfoot Cafe about 260m away
Straight-line distances from OpenStreetMap, not walking distances, and only what volunteers have mapped — something missing here may still be there.
Getting here without a car
- Nearest bus stop Southlands Road (W-bound), Buxton Road, about 670m away
- Nearest railway station Weymouth Rail Station, 2.4 km away
Straight-line distances to where the stop or station is, from the national registers of them. That a stop exists is not a promise that a bus calls at it — timetables are somebody else’s data and this page does not read them, so check the operator before you rely on it.
The record since 2020
In 2025, the 5 monitored overflows the Environment Agency lists against this bathing water spilled 19 times, for about 6 hours in total. Over the 2025 bathing season alone, 1 May to 30 September, 10 of those spills happened — 53% of the year.
- 20205 spills · 3 hours
- 202116 spills · 3 hours
- 202213 spills · 2 hours
- 202332 spills · 17 hours
- 202427 spills · 8 hours
- 202519 spills · 6 hours
These are annual totals for the whole year, not readings from today — today’s answer is the verdict at the top of the page. Figures come from the Environment Agency’s Event Duration Monitoring annual returns, which the water companies submit and the EA publishes, and the EA decides which overflows count as belonging to this bathing water.
What the regulator says about this beach
From the Environment Agency’s published bathing water profile for 2026. It describes the place and its catchment, not today’s water.
The beach itself
Portland Harbour Sandsfoot Castle is in Portland Harbour on the Dorset coast. It is a sheltered sandy beach, approximately 300 metres wide, backed by cliffs.
What drains into it
The catchment surrounding Portland Harbour Sandsfoot Castle is approximately 15 hectares. Land use is urban and there are no streams which drain directly to the beach.
More from the profile
Where the sewage works discharges
Sewage from the Weymouth and Portland area is treated at Weymouth STW and discharges to the sea one kilometre offshore, west of Portland Harbour. The discharge is designed to protect water quality.
What has been done about it
A resewerage programme in the Portland catchment, which included a pumping station and attenuation storage, was completed by Wessex Water in 1996. Unsatisfactory combined sewer overflows were improved by attenuation storage in 1996. Improvements to the storm overflows at Wyke Regis (Doncaster Road), and Doncaster Road were completed by April 2002.
What the samplers see on the sand
Environment Agency samplers make observations of litter present on the beach at every visit, this includes assessments of sewage debris, litter and tar. At Portland Harbour Sandsfoot Castle for the four year (2022-2025) assessment period where data is available, sewage debris was not noted at this site. Litter was not assessed as being sufficient to be objectionable, but was observed as being present on 71% of visits. Tarry residue was not noted at this site.
Published by the Environment Agency under the Open Government Licence. The full profile carries more, including sections repeated for every beach that are not reproduced here.
Other swimming spots nearby
The closest bathing waters on the regulators’ lists, straight-line distance. Each has its own checks and its own verdict.
Check the official source
The regulator’s own page for this bathing water. If it disagrees with this one, believe theirs.
Portland Harbour Sandsfoot Castle's official page at the Environment Agency · See it on a map
This page is not official. It reads published data and presents it plainly; if a sign at the beach says otherwise, believe the sign.
If you get into trouble
This is the RNLI’s advice, not ours.
Float. Tilt your head back with your ears in the water. Relax and let your breathing settle. Move your hands and legs gently to stay level. Your legs may sink, and that is fine, everyone floats differently. The first shock of cold water passes in less than a minute, so do not try to swim straight away. Once it has passed, call for help or swim to safety.
Caught in a rip current? Do not swim against it, you will only tire yourself out. If you can stand, wade out of it. If the water is too deep to stand, swim parallel to the beach until you are clear of it, then head for shore. Raise your hand and shout for help.
Nobody publishes a rip current forecast for beaches in Britain or Ireland, so this site cannot show you one. The RNLI has one for its own lifeguards. The public does not. Look at the water before you get in, and look for a channel where the waves are not breaking.
In an emergency call 999 and ask for the Coastguard. In the Republic of Ireland call 112 or 999 and ask for the Coast Guard.
Where there are lifeguards, swim between the red and yellow flags. They put those flags where it is safest that day and move them as the sea changes. A red flag means do not go in, whatever this page says. An orange windsock means the wind is blowing offshore and inflatables should stay out of the water. Most places on this site have no lifeguard at all.
This advice is the RNLI’s. Their Float to Live pages are worth two minutes of anyone’s time.
Use this page elsewhere
One sheet of A4 with a QR code to this page, for a clubhouse, a campsite reception, a surf school or a harbour office. The address is printed underneath in words, so it still works for anybody who would rather not scan a code.
Print a sign for Portland Harbour Sandsfoot CastleOr put today’s verdict on your own site.
Put this beach on your own site
A small card showing today’s verdict for Portland Harbour Sandsfoot Castle, updating itself. Paste this where you want it to appear. It loads nothing of yours and sets no cookies, and it costs your visitors about ten kilobytes, most of it the readings themselves.
Click the box to select it all. There is also a feed for this beach, if you would rather be told than have to look.