Did German U-boats land on remote spots in Britain to take on freshwater?

Hello Indy and the rest of the Timeghost team. Thank you for a unique and wonderful series.
I recently read an article on a Uk climbing website about some rock climbers who did a climbing traverse of the cliffs below Exmoor on the Bristol Channel. The article mentioned that in WW2 a German U boat anchored by Sherrycombe Waterfall at night to obtain fresh water. This waterfall tumbles down the cliffs and the bottom is inaccessible except by boat (or by rock climbing).
Has the team heard of this story or of other occasions where a U boat anchored off Britain to obtain water or other supplies?