An additional thought:
The gravitational mass of heavy fins is largely offset by buoyant forces underwater but inertial mass is unchanged.
If you’re going to be doing a long swim, you might want to think about the extra work required to repeatedly kick with heavy fins.
Ive never had issues but I’ve seen several others have fatigue problems exacerbated by using heavy fins. YMMV
The gravitational mass of heavy fins is largely offset by buoyant forces underwater but inertial mass is unchanged.
If you’re going to be doing a long swim, you might want to think about the extra work required to repeatedly kick with heavy fins.
Ive never had issues but I’ve seen several others have fatigue problems exacerbated by using heavy fins. YMMV