Sea Swimming and Tides: When to Swim Safely in Ireland

The tide decides more about a sea swim than the weather does. It decides how far you walk to get wet, whether the ladder reaches the water, and where the currents run. Here is how to pick the right part of the tide for the kind of spot you swim at, and the safety advice from Water Safety Ireland that goes with it.

Match the tide to the kind of spot

Shelving sandy beaches

Portmarnock, Curracloe, Banna, Salthill, Rosses Point: long, flat strands. At low water the sea can be several hundred metres out, knee deep for most of the way. Swim in the hour or two either side of high water, when deep water comes close to the dry sand. Our beach pages list a daylight window around each high water in the “Best times this week” table.

Steps, ladders and bathing places

The Forty Foot, Seapoint, Vico and the Blackrock diving tower at Salthill work on height, not time. At a low spring tide the bottom rung can be well above the water, and diving boards become dangerous. Go from mid tide up and look at the height next to the time, not just the time: a low water of −2 m on a big Dublin spring leaves much less water at the steps than a −0.6 m low at neaps. The exception runs the other way at Kilkee, where the Pollock Holes rock pools are only reachable around low water.

Steep shingle and stony beaches

Bray, Greystones and Kilcoole: the beach drops away fast, so the water is deep at any tide. That makes timing less important and the shore break more important. Waves dump on the steep bank, and getting out is harder than getting in.

Estuaries, harbour mouths and channels

Do not swim across channels or near river mouths on a falling tide. The ebb from a whole bay or estuary drains through the gap, and it does not slow down for swimmers. Inch and Rossbeigh in Kerry, the channel at Tramore’s Back Strand and the Garavogue at Rosses Point are known examples. If you must swim near one, go at high water slack, when the current briefly stops.

Rip currents

Water Safety Ireland calls rip currents the leading surf hazard for beachgoers. They are narrow belts of water flowing out to sea, forming where waves break strongly in some places and weakly in others. They usually flow through low spots or gaps in a sandbar and beside piers, rocks and groynes. Typical speed is 1 to 2 km/h, but speeds up to 8 km/h have been measured, faster than an Olympic swimmer.

Look for a channel of choppier water, a different colour, foam or seaweed moving out, or a gap where waves are not breaking. They are often hard to spot. The tide changes them: on many Irish surf beaches rips run hardest on the falling tide, when water that has come in over the bar drains back out through the gaps.

If you are caught, Water Safety Ireland’s advice is:

Stay calm. The current takes you out, not under.
Do not swim against it. Swim parallel to the shore until you are out of it, then swim in.
If you cannot, float or tread water, raise an arm and shout for help.

Cold water

Irish sea temperatures run from about 8 to 10 °C in late winter to 15 to 17 °C in late summer. Sudden immersion in cold water triggers cold water shock: a gasp, fast breathing and a racing heart in the first minute. Water Safety Ireland’s advice is not to jump in. Walk in slowly, splash your face, neck and shoulders and breathe calmly before you start swimming. If you get into trouble, float on your back (“Float to Live”) until your breathing settles.

Winter swimming is popular around the Dublin and Galway coasts. Keep it short, stay within your depth, never swim alone, and have warm clothes and a hot drink ready. After a winter swim your body keeps cooling for a while after you get out, so dress quickly.

Before you go

Tide. Check today’s times and heights on your beach page. Note high water and whether the tide is rising or falling when you plan to swim.
Wind and swell. An onshore wind and swell make a beach rougher and rips stronger. The Met Éireann sea area forecast gives wind for the coast.
Flags. Red and yellow flags mean lifeguards are on duty: swim between them. A red flag means do not swim. Lifeguards cover selected beaches at weekends in June and every day in July and August.
Water quality. After heavy rain, sewage overflows can close a beach. The EPA’s beaches.ie shows current bathing water alerts.
Emergency. If anyone is in difficulty in the water, call 112 or 999 and ask for the Coast Guard. Throw a ring buoy if there is one. Do not go in after them yourself.

Tide predictions ignore weather, so in a storm the water can be higher than the table says. The tidal walks guide covers the other half of the beach day: the time on the sand at low water.

What is the best tide for sea swimming?

On a shelving sandy beach, the hour or two either side of high water: the water is deep close in and you are not wading out over hundreds of metres of sand. At steps, ladders and piers, mid tide to high tide, so the ladder reaches the water. Avoid the falling tide at surf beaches, when rip currents tend to be strongest.

Is it safe to swim at low tide?

It can be, but low water on a flat strand means a long wade, cold shallow water and channels that run hard as the flood starts. On steep shingle beaches like Bray or Greystones the water is deep at any state of tide, which brings its own risk of a sudden drop.

When are lifeguards on duty in Ireland?

Water Safety Ireland says lifeguards are at selected beaches at weekends in June and full time in July and August. Check the list for your beach on watersafety.ie or with the local council, because hours vary.

What do I do if I am caught in a rip current?

Stay calm and do not swim against it. Swim parallel to the shore until you are out of the current, then swim in. If you cannot, float or tread water, raise an arm and shout. If you see someone else in trouble, call 112 or 999 and ask for the Coast Guard, and throw them something that floats.