WYDT
Contributor
Duncan Price once bubbled...
Oh .... at they are not filled with clear warm water either.
There are lots of caves filled with clear warm water... maybe not in the UK but in FL, Mexico, Dominican Rep., Brazil, Saudi Arabia... etc. etc.
I'd put sumps in a totally different category than cave diving. None of the cave divers I know have any interest in dry caves or 0 vis 50 degree water.
DSAO!