[Mullins]

I think a slightly lower amplitude works with hyper-style fins simply because the blade is positioned further from the feet, so the trailing edge moves further for a given kick amplitude than that a regular mono. The higher angle between blade and footpocket also helps. However the big dead-spot you get at the top and bottom of the stroke with these fins (because the footpockets do the flexing and the blade stays almost flat) puts a limit on how narrow the kick can be. Also, they're quite heavy so a narrow, rapid kicking style is going to waste a bit of energy simply changing the fin's direction more often.

What Max says on his site about the benefits of using fibreglass and the poor elastic qualities of rubber is a little contradictory in the context of hyper-style fins. If rubber dissipates so much energy as heat, why use it as the main elastic component? (I'm assuming this fin acts like the others I've seen i.e. the footpockets do all the flexing, not the blade. This is supported by the comment about the 'feeling of shock absorbers.' Surely you want transmission, not absorption?)

As for v-bend... a little is probably not going to do much harm. However I'd like to see what that fin looks like under load Fondueset, I suspect it might get quite a bit worse when kicking against buoyancy. Any chance of a side-on video to show 1. how much it v-bends and 2. how much of the blade's pitch comes from the footpockets?

I'll post a video up at some stage of how my Hyperfin looks in the pool under only moderate load, it's pretty bad! Both of those behaviours are quite pronounced. It is the best fin I've had to date and I can swim pretty good distances with it, but that doesn't mean its performance couldn't be better.

Also, Max is saying above that v-bend is caused by the blade being too long and soft. This seems rather strange. The short hyperfins like mine seem to be among the worst culprits. My Leaderfins Hyper Freediving is an unusually long fin and doesn't v-bend at all. It's also soft due to its length.

I think the Hyper-style fins are the best available and this one looks great, I just think some of the claims made about them are either over the top or contradictory. It would be interesting to make a lightweight fin with rigid footpockets, lots of angle, a blade that flexed without v-bending (!) and a bit of distance between the footpockets and blade. I.e. all the good points of hyper-style fins without the bad bits. Personally I'd also like to lose the rubber wings and see how that went.