It might sound like another example of a council going daft but an island in Wales is being equipped with a set of traffic lights, even though it has no roads or residents, after visitors keep getting cut off by the tide.

Sully Island, located of the coast on the Vale of Glamorgan, can only be reached by foot via a rocky causeway which appears at low tide. However, over the years hundreds of visitors have been left stranded by being caught out by the tides, which has resulted in a series of call outs for the local lifeboat. A group of nine people had to be rescued from the island over the last Bank Holiday in May, even though the island is only 400m from the shore.

There is just a three hour window for people to get across the causeway to visit the island either side of the low tide. It has become a popular attraction in the area, especially for those wanting to visit the Danish Iron Age Fort and the remains of a Victorian ship which ran aground on the island.

The traffic lights are being installed as a bid to reduce the number of call outs for the RNLI by warning visitors about the incoming tide. The lights will let people know when it is safe to cross, when time is running out (as it takes around 40 minutes to make a return journey) and when it is considered unsafe to cross. It is hoped that by observing the sign people won’t have to second guess how much time they have, and so reduce the number of required callouts.

The sign is the first of its kind in the UK and if successful it could be introduced at other sites around our coast. So if you are planning a visit, you will need to check the lights when you arrive, or you might need your wellingtons to get home.