I have to say I’m not following this.
I have two conflicting prejudices here. First of all, I dive Jets, both extra large and 2xl. I have very high arches, so the foot pocket can be punishing. But with the right shoes underneath, I find them to work extremely well, especially with a dry suit.
Second, I think squats are probably the best exercise that you can do: they work most everything from your neck to your heels, all at once. So any fins that allows me to make my squat-strengthened legs more effective gets my vote. So I’m very intrigued.
But I have no idea what you mean about finning through your toes versus finning through your heels. Nor can I figure out how the foot pocket not being *longer* prevents this from happening. I would love to hear more details.
In the interim, I’m going to make an assumption: the problem is not the fins, it’s the boots.
The foot pocket really only has one job: hold the fin to your foot. If the fin doesn’t slip off, the pocket has done its job.
I wear a size 12 1/2 US Men. Even the smaller of my jet fins fit over about half of my foot. If they went too much farther, it would only make the foot pocket problems worse, because it would come up higher on my arches. And in the end, it couldn’t go that much farther on anyway, because my ankle would be in the way!
In the end, it’s not the responsibility of the fin foot pocket to determine what happens with your foot. It’s the responsibility of whatever shoe-like object you’re wearing between your foot and the fin.
Now, if you’re wearing some completely soft and flexible water shoe that they might call a “boot”, well, your foot is going to be able to flex all over the place. And you’ll have to use a great deal of foot muscle power to stabilize your foot – something it is not inclined to do. But that’s not the fault of the fin. That’s the fault of the shoe.
After all, my understanding is jet fins were originally designed to be worn with combat boots. You’re not going to get any foot flex in that case.
I just recently decided to use Converse All-Stars as my boots along with the neoprene socks on the end of my dry suit. That is what forced me to have to go up to the 2XL jets. And it’s not like those shoes have some ultra stiff sole. But it is certainly plenty stiff enough. And that allows all of the support I need to be able to fin with tremendous force, either frog or flutter.
It’s no different than other similar applications. I ride a race bicycle. The soles of the shoes you wear with the clipless pedals on such a bike are literally plastic-rigid. And that is intentional: you want no flex in those shoes. You need to transfer maximum power from your legs through your feet into the cranks. If there’s any flex, you will rapidly fatigue the muscles in your feet and cause a great deal of pain. If you’re just riding around town on platform pedals, then yeah, you can get away with flip-flops or whatever. But not if you care about performance or endurance.
When you’re trying to apply lots of force for a long period of time, you need the right equipment – and *all* of the right equipment – to get the best application. That’s just as true in scuba.
So, that’s my unasked for and potentially misguided thoughts on scubapro jet fins and why so many people have problems with them. Of course, they’re not the right fins for everyone: like others have said, they’re quite negative and almost board stiff. They’re not at all forgiving for casual use. Like race bicycles with race shoes.
But when you want maximum performance pushed into the water for an extended period of time, they’re pretty hard to beat.
ETA: please don’t take this as me saying that you’ve done anything wrong, or that your opinion is wrong. It no doubt comes across as condescending and unasked for, probably because it is.

. But if you don’t like jet fins, then by all means don’t use them. I’m not trying to talk you into or out of anything. I just wanted to write some thoughts about what I have personally found often makes people blame their fins, no matter what brand, for failings of their boots. Makes a big difference when you have the right foot gear for the job. (I have the same problem with people complaining about how “uncomfortable” performance bicycles are.

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