Hey guys,
The PFI Team, mainly Kirk and Mehgan, also started using the Mustangs with mixed results from what I could gather from Kirk. Sent him a different size foot-pocket than the ones we had originally and he seems to like them much better now.
Syn I think if you're purely going to concentrate on depth and not going to be fishing with them Mustang 80's would be the best and only candidates for you in the 80 grade fin since it's the only 80 C4 still currently produces. Keep in mind a mono-fin is not for everyone and if you're not a stronger butterfly kicker than a freestyle/scissors kicker they will actually hamper you a lot. I hate mono-fins because when I swam in college my butterfly kick was horrendous and I am as good at moving my hips as I was at my first highschool dance
There is another point I left out in my previous post where I have to agree with Bill. The Mustang foot-pocket either fits you or it doesn't. It could be more universally fitting when a softer compound version of the pocket comes out next year. While mine are the correct size for my foot (47-48/13) there is a an overwelming sensation that the pocket is a bit overbearing after prolonged use and envelopes your foot so thoroughly it feels more like a snowboard boot and binding or a hiking boot compared to a traditional fin foot-pocket. This is not necessarily bad, rather it's invasive in a good way. In other words you're in there when they're on and laced up.
This is the reason I go back and forth between what I retain are the two best fins currently in production right now in my experience selling and using long fins all these years, the Rekord 3 and the Mustang Super Falcon 30. After using both of these even the Falcon 30's or 40's that were my favorites seem a much lesser fin now-a-days, and I think the Falcons have the best track record of any other carbon fin on the market thus far. The Rekord 3's are a bit less overwelming than the Mustang/SuperFalcon, easier on the foot, more comfortable in 30-80ft or so and less invasive. I should clarify the Super Falcon is just a Falcon shaped blade version for the Mustang footpocket system. But in a situation like this past weekend when we were diving 100'115' for Cubera snapper the SuperFalcon 30 is definitely a better deep freediving fin.
What I meant by a more natural kick was that the Mustang pocket is ergonomically shaped to the foot much more than a regular flat pocket. Just like the bend in the blades, the pocket is bent as well and conforms to the shape and angles of the foot. The shorter kicks with more repetitions or slower kick with longer strides have nothing to do with this, that is more the function and length of a blade (short scuba fin/longfin kick). I didn't really want to get into all the fin mechanics and drag this out because articulating this is much harder for me than just showing someone in a pool. Proper fin mechanics like swim mechanics take time and experience to develop and some have different styles that vary in efficiency but in a nutshell:
When you kick or swim down the pool without fins you don't drop your knees. Your kick is more like a boat prop's with a shorter stroke and your feet flap rapidly up and down after you followed it through by your power kick from the thighs/shaft and to a lesser degree leg below the knee joint. In other words your thighs are always your primary muscle, the lower leg below the knee joint secondary and the feet like a prop just do in motion what comes as a result of the prior two.
Using long fins the correlation changes. A much lower rpm stroke from the thigh follows by dropping your knee more to keep from splashing the fin out of the water with the extension which is then followed through with the kick of the fin. Here you let the efficiency of the blade go through it's motion and make it's sin curve to get the most efficiency out of the fin. That's where the difference in blade stiffnesses comes in...to further optimize this relationship.
When you kick without fins you don't do this because your feet are short so you don't drop your knees and rely on your feet nearly half as much to pick up the slack.
Having said this I don't know if I'm making any sense here because swimming and fin mechanics are not so strait forward otherwise everyone would be an olympic swimmer. However, as it relates to the C4 Mustangs there is less bending and knee dropping going on to get the most efficiency out of the fin and this translates into a more comfortable and natural kick - at least that's the theory!
