I wear and recommend Force Fins and can kick against the wind and current without fatigue.
I always GPS my distances on the Run Keeper app and have regularly gone distances of 1.5+ miles per session, no problem at age 65.
The only negative point about the Force Fins is that they don't float, they sink. So I wear fin leashes .... problem solved. They normally cost $225.00 new but I purchased mine on eBay used for $81.00.
I normally wear a size 10 shoe. But with my Simm's sock foot waders and a size 13 pull over water shoe over the sock foot, I comfortably wear a size XL in the Force Fin.[You must be registered and logged in to see this link.] [You must be registered and logged in to see this link.] [You must be registered and logged in to see this link.]
Dr Harvey Barnett is an underwater photographer, researcher and waterman. He conducted research proving the physiological advantages of Force Fins.
His research was comprehensive, monitoring things like carbon dioxide uptake, lactic acid production, fatigue factors, in many different individuals, wearing many different flippers in controlled situations in a pool.
Force Fins proved to be so vastly superior to anything else that he personally tested, that he has worn them ever since. [You must be registered and logged in to see this link.]
You would probably wear an XXL FF if you wore a pull-on water shoe. Avoid zippered water shoes and get as thin of a water shoe as possible.
Good luck on making your fin decision, so many fins out there to choose from.
SP Dan <"))><