These fins are a 100% pure carbon fin made in the UK in "medium / 25" stiffness and the "standard" Pathos Fireblade footpocket (size 40-42). Dave who owns the company was extremely responsive to inquiries and will help you determine the best choice for you if you have any questions.
SEXY! I say that not ONLY because of the letter "I" in their logo... but because they are a no-nonsense, high-performance, super lightweight, purpose built pair of race cars that you slip on your feet.
This footpocket has taken the freediving and spearfishing world by storm...and for a good reason. It has been around for more than a couple of years, but has really caught on like wildfire recently and rightfully so. It is by far the lightest footpocket on the market and having said that... it delivers great power transfer! This isn't hard to do in a heavy rubber footpocket with thick / stiff tendons, but is an engineering feat in one that is lightweight.
The area below the "Fireblade" wording is stiff and fairly shallow to help accommodate this. People with a high arch may find it quite tight and indeed so are mine initially. Having tried my friends' when new and then 6-mos later, I can attest that they will loosen up a bit to accommodate your foot shape. Another way to speed the process up if you are in a hurry, is to (while wearing your intended socks - or a pair of cotton / wool if intending barefoot) heat them up while wearing them with a hair dryer and allowing them to cool back down again and mold to your feet. It might make sense to keep track of L & R in this instance.
I have fairly wide feet and find these fit my feet great.
Typically I would tend towards something stiffer than most "medium" stiffness blades, as I consider myself a strong kicker, I'm 80kg, often dive in a 5mm suit (more buoyancy change than a 3mm) and can dive deeper than many recreational divers and spearfishermen. I also would rather a fin be slightly too stiff, than not stiff enough as I like to have extra "power" in reserve in case I have to rescue a blacked-out diver while safety'ing.
These Mediums fit my needs perfectly. They are stiffer than most mediums but not considered a Stiff. In fact, I would consider them to be about 1/3 of the way between a medium and a stiff blade.
Note: Several friends have the Leaderfins fibreglass fins with Leaderfins footpockets and some of the stronger / more aggressive finners have commented that the mediums are slightly on the soft side. Just important to keep in mind that all "mediums" are not the same - even when retailed by the same company (as they are manufactured by separate companies, materials and using different methods).
A beautiful, nice progressive flex under load that snaps back to straight quite smartly and provides you with some extra thrust. You get an energy payback from the the previous input.
Below is a video of a friend using this exact combination in a pool doing a dynamic swim, not under load and at the time he was a new freediver who had previously only swam 75m. Using less knee bend would highlight the fins progressive flex better, but a good video nonetheless.
The rail on the side of the fins is tall to help channel the water effectively yet supple enough to bend /flex under load without crinkling or deforming.
- Surface swimming:
Compared to all of the other fins that I have ever tried, it doesn't feel like you're wearing anything on your feet due to the super light weight combination of the Pathos footpockets and the light carbon blades! Less power is spent moving and stopping the mass of the fin so that more of the energy goes towards propulsion.
I've used carbon / kevlar blades previously, but when paired with a heavy Omer Stingray foot pocket it really weighed the pair down and made it feel like you had appendages on your appendages. Not so with the 'Pure Evolutions'.
I find that surface swimming is more tiring than any other type of activity in the water and I often pace myself on the swim out vs. getting to my dive site quicker and tiring my legs out (and increasing my heart rate) before I get to the dive spot. These 'Pure Evolution' fins make the surface swim significantly easier and is much less tiring on the quads during the swim out, saving them for your depth diving.
This is even more so the case with spearfishing from shore, as fighting the tides and getting beyond the breakers of a reef can really burn out your legs early and limit your abilities while spearing and reduces your 'safety envelope' while out there. Save the legs for a safer diving experience.
- Down to depth and back again:
During a line-diving outing (to -25m), I found that I wasn't having to "muscle" the blades in both directions on the descent to get a good sine wave going. The fin was loading up nicely and then returns back to straight with assertive authority, almost a snap, so you end up getting a lot more propulsion per kicking cycle. They are extremely responsive and was requiring fewer kicks to get to the same depth.
On ascent, the same ease of propulsion is again quite evident. What I noticed however is if I wanted to get back to the surface quickly or did a couple of dolphin kicks, I would really rocket up!
In general, a more gentle / energy efficient kick is preferred for O2 conservation but it is always nice to know that you can lean on them for a bit more thrust if / when needed. These will certainly shine in the deeper dives to come.
These Fins4u.com 'Pure Evolution" 100% carbon fins paired with Pathos footpockets are a fantastic no-compromise pair of fins. They are super-light, efficient, comfortable and as a bonus, are less $$$ than some other big-name 100% carbon fins and come in a superior foot pocket. Highly recommended!
Word of warning:
If you buy these fins, you will need to come up with a new excuse! :D