Stuart Thompson, from the RNLI, says one of the risks of tombstoning is the sheer unpredictability of the environment.
"The problem is that you know heights of tides change, conditions change" he says.
"The conditions of the seabed change as well so it's actually quite a dangerous practice".
More top news
Andrea Byrne presents the third episode of Helimeds following the helicopter crews of the Wales Air Ambulance.
The heaviest of the rain clears overnight leaving a much drier and brighter picture for the weekend!
Thunder and lightning brought a warm and dry start to September to a soggy end. But how are we looking for the weekend?