Most mats don't use fins and they are ridden with low pressure because (counterintuitively) they perform better that way. I spent a winter trying to master it. Not easy and, imho, not nearly as good a tool as a well-designed sponge. A sponge (boogie board) is probably the best all around surfing machine for smaller to medium barrels and in the right hands will perform in very large, hollow waves. Not so great in huge waves where long distances need to be traversed and big chop is a factor. There are people who make the mat work very well. Mike Stewart designed a "big boy" bodyboard which works very well for us bull seals.