This is Clearly Not made by people who swim often: the foot is oriented at 90° which feels like wearing a floating anchor! For better hydrodynamics they could add a very simple "ankle joint" that can be unlocked (like a locked knee system for AKAs), allowing the foot to freely flex backwards up to 180° when swimming. Want to walk? Simply put down your foot and pull the lock. This type of swimming foot already exists for amputee scuba diving and finswimming, btw. (You can walk to the water, put on an ordinary fin and unlock your ankle to start swimming.)

Did they lose them in a war?how many?from non combat from a 17 yr war?war is a big business it seems?

I've disabled it and have a prosthetic leg but I can't barely walk with or anything with it I wish I could swim the damn what wish I could swim and it looks like it would help you to learn how to walk better like I say I have to use a peg leg to get around because I cannot engage my knee without falling because I just it's my dominant leg that's gone please help me and my name is Roy Summers I'm on SSDI I would love to be able to go into the ocean or into up swimming pool in actually swim or walk around in the pool without falling over God bless whoever designed this thing