I mean swim fins also propel swimmers at superhuman speeds (aside, it would be really cool if there was a proper competitive community for stuff like that, like

I mean swim fins also propel swimmers at superhuman speeds (aside, it would be really cool if there was a proper competitive community for stuff like that, like how on land we have races for runners and races for cyclists; edit: Google informs me the competitive sport has world championships and is called "finswimming"). Is there any quantitative comparison between this doodad and fins? It doesn't even have convenience going for it since you have to strap into it, so it's probably almost as much of a ball-ache to put on as fins, plus the awkward problem that it's hard to stand up. If they can make it work without the waist strap (or have super-quick disconnect for that strap) I could see that convenience being nice, but still, I'd like proper comparison with fins.