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".
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Winter sunshine with cloud creeping in during the afternoon and a frosty night ahead.
The Revd Canon Joanna Penberthy has been consecrated as Bishop of St Davids in "an historic" day for the Church in Wales.
Temperatures will tumble under clear skies tonight with a widespread frost developing.