Ohhh, that is ok then, we will walk the swim 
Well, I want to hire the wetsuit, so that if I dont like it or if my back causes me grief again, I get £75 back when I return the suit and it has only cost me £25 plus the postage. On top of that I wont have a wetsuit lying about the place that I will never use again.
I have no issues with them taking the value of the suit off my card for the duration of the hire, seems sensible practice from a rental point of view...