I initially tried the Mares Razor longfins, but found them too pliant. A stiffer blade suits me better, as I’ll end up churning water with flexible fins. The Cressi 2000 HF is stiff enough without being terribly expensive—but given that a good pair of fins will last for a few years of heavy use, just go for what’s best!
Descending at Airport Beach, Maui.
I sometimes think an even stiffer fin—carbon fibre, for example—would suit me even better. But given that I have no discerning reason beyond “maybe it’d be better”, I’ll stick with what I have.
I also worry that an even stiffer fin will cause too much abrasion in the foot pocket. As it is, I’ll avoid using the 2000 HF for long surface crawls to keep my feet in one piece.
Equalising on descent in our “Blue Dive”, Hawai'i.
I warn you, however—the 2000 HF needs a bit of muscle behind the kick! So if you’re going to surface crawl or lots of paddling, you can expect to get pretty winded regardless the speed of travel. The extra power really shows in descent and ascent times, however.
I also tend to wear a fin sock at all times to prevent abrasion around the heel: a simple 2 mm sock in warm water up to a 4 mm open cell (the lack of lining makes them thinner in practise) in colder waters.
Enjoy your Cressi longfins, and safe diving!