Marine Lake sits right on Weston’s seafront, held in by the causeway between Knightstone Island and the shore. When the tide goes out across the bay, the lake stays full – so you can swim, dip or paddle at any time of day, all year round. There’s no booking and no charge: just turn up.
Before you swim
The lake is much calmer than the open sea, but it’s still sea water and there are no lifeguards. A few simple habits keep everyone safe:
Bring a buddy
There’s no lifeguard at the lake, so swim with a friend and keep an eye on each other.
Never jump or dive
Much of the edge is less than a metre deep. Get in slowly using the steps.
Respect the cold
The water is chilly for most of the year. Acclimatise gently and warm up quickly afterwards.
Watch the big tides
On the highest spring tides the sea washes over the causeway. Stay out of the water and off the causeway when it does.
Keep children close
Always supervise children and anyone who isn’t a confident swimmer.
In an emergency
Call 999 and ask for the Coastguard. The location signs at each entrance tell them exactly where you are.
If beginners’ sailing boats are out on the water, please keep to the beach end of the lake and give them plenty of room.
Water quality
During the bathing season (May to September) the water is sampled regularly and we post the latest result here as soon as we have it. Results use the same scale as UK bathing waters: Excellent, Good, Sufficient or Poor.
Lake updates
- The lake is Open
- Water quality Excellent
- See for yourself Live webcam
Why is the water brown? It’s silt, not dirt. The Bristol Channel has one of the biggest tidal ranges in the world, and the sea that tops up the lake carries fine mud with it. We’re fundraising so the water can be tested all year round, not just in summer.
Getting here
Marine Lake
Knightstone Road
Weston-super-Mare
BS23 2BE
- By car: the nearest large car park is Melrose pay-and-display (BS23 2AW). Parking right by the lake and in nearby streets is limited, especially on sunny weekends.
- By train: Weston-super-Mare station is around a 20-minute walk – head down to the seafront and turn right towards Knightstone.
- By bike: there are cycle racks around the lake.
At the lake
Toilets
Public toilets are next to the lake, including an accessible toilet added in the 2026 improvements.
Getting in
New steps, ramps and handrails make it easier to get in and out of the water.
Coffee & hire
Since the lake reopened in 2026 there’s a coffee hut, paddleboard hire and a sauna by the water.
No changing rooms
Come ready to swim and bring a changing robe or towel – and something warm for afterwards.
Got a question about the lake?
We’re a friendly bunch – drop us a message and a Mudlark will get back to you.