Barry Dock RNLI volunteers were called out yesterday afternoon to assist four boys from Bristol who were cut off by the tide at Sully Island.

South Wales Police said: ''Penarth NPT assisted the Coastguard after four males were cut off by the tide on Sully Island. All four had travelled from Bristol for the day. Appropriate action was taken.''

This was the third call out for the volunteer crew in over two weeks to people attempting to walk to Sully Island.

The volunteer crew were requested to launch the D class inshore lifeboat at 4 pm yesterday afternoon (Monday 6 April) to assist four people cut off by the tide. The lifeboat recovered the group and they were taken back to shore.

An RNLI spokesperson said: 'The RNLI's priority is keeping people safe in the sea and around our coast, as it always has been. At a time when emergency services are already stretched we ask everyone to follow government advice about leaving home to exercise.

'If you live close to the beach and are choosing to use it for your exercise, please make sure you check tide times, your route and local conditions before setting off. Whatever form of exercise you chose, please follow the government's instructions and avoid taking unnecessary risks which will put pressure on our volunteer lifeboat crews and other front line services.'

RNLI volunteers are regularly called to assist people who have been cut off by the tide at Sully Island, these call-outs always increase during good weather. This is why it's now more important than ever to check the digital crossing sign near Sully Island and the tide times.

If you do choose to exercise on the coast, the RNLI water safety advice is:

• Take care if walking near cliffs - know your route and your limitations

• Check the weather forecast and tide times before you set off

• If going afloat, carry a means for calling for help and always wear a lifejacket

• If you fall into the water unexpectedly FLOAT TO LIVE. Fight your instinct to thrash around, lean back, extend your arms and legs, and float

• In any coastal emergency, dial 999 or 112 and ask for the coastguard