Hi, I am new to freediving and try to go as much as possible. I have a pair of Cressi Gare freedive fins and I really like them however when I have gone freediving I tend to swim on the surface rather long distances before diving. Firstly I cant seem to get the right techinique for this as I feel very slow and like im having to put alot of energy in and secondly by the end of my session the front of my ankles ( I dont know the actual term for this part of the body) are in agony, they feel so stretched by the force of the fins and I assume this is connected to a bad technique or maybe it just takes time to get used to? When I actually dive they feel fine its just swimming on the surface that seems to be the problem. Any advice as to what I could be doing wrong would be appreciated. Also my fins may be slightly too big however I have thick neoprene socks that fill them out nicely.