Bob was gracious enough to loan me his pair of SD1 Military Force Fins and he felt these were the force fins best suited to the type of diving I do.
SD1 Military
I am primarily a Cave and Wreck diver and I can't remember the last time I dove a single tank, and more often than not I have a deco bottle or a stage and deco bottle along as well. So I have a strong bias toward large stiff bladed fins like the Scubapro XL and XXL Jet Fin or, even better, the slightly stiffer and equally large XXL OMS Slipstream - a monoprone clone of the Jet Fin.
I tried the original Force Fins a long time ago and I have never been overly tempted to buy a pair. But since Bob was kind enough to let me demo his personal fins and shipped them 3000 miles to the east coast, I figured I would give them an honest try.
I did a normal dive at the local quarry in my Fusion dry suit, Evo 3 boots, doubles and a deco bottle and used them in the same manner I would in a normal cave dive (frog kicks, back kicks, very limited modified flutter kicks, etc) for silt prevention. I noted several things:
1. The foot pocket is very well designed, is quite comfortable even with wide feet and large boots and will fit just about anything. There are a couple straps across the arch, but 10 seconds of thought on the matter is all that is needed to figure out how to tuck them away (I chose to fold the loose ends back underneath the upper velcro flap, which worked quite well.
2. They frog kicked much better than I expected. They track well through the water but do feel different (more on that later). They do not have the brute accelleration or the top end speed you get with a large stiff fin like the OMS Slipstream or XL Jet Fin in a set of doubles, but they did a respectable job with very little muscle required. Not the fastest car on the track, but very efficient.
3. They were very easy to back kick in. Much to my surprise they backed up easier than any fin I have ever used - much like back kicking in a pool with no fins at all, no intuition or practice required - it just happens. Again, they were not real fast, but very easy and with minimal muscle required even with doubles and a deco bottle.
4. Helicopter turns go reasonably well, but lack the precise feel of a Jet Fin during that evolution. Not bad though and much better than I exepcted.
5. Flutter kicks were also lacking in brute accelleration and power compared to a Jet Fin, but they are a big improvement over the original Force Fins when you have lots of mass to move in the water, and again they seem to require very little muscle power.
6. They are different though and they apparently use some different muscle groups, at least when primarily frog kicking as 20 minutes into the dive the muscles in the upper outsides of my thighs were starting to "feel the burn" so to speak. This was a bit of a surpise given that my legs are quite happy and complaint free after propelling me on 2 hour cave dives in Jets and Slipstreams. I expect over time, your legs would adapt, but it is different and would take some adjustment.
My conclusions were:
A. They do not have the same brute power and instant accelleration I like with my Jets and Slipstreams, but then you wouldn't have to have large legs to power them either. And in applications where you do not need that much brute power (single tank wet suit diving) I can see the appeal.
B. They are better than any of the several spilt fins I have tried over the years (at least in a set of doubles) in terms of frog kicks, back kicks and even accelleration.
C. They were a lot better than I expected. They don't have enough power to seduce me away from my Jets or Slipstreams, especially in current or a high flow cave, where you sometimes need power right now and lots of it. On the other hand, if they came in a version with a significantly larger blade that would offer a little more initial snap and a little higher thrust, especially in a frog kick, I could envision myself being tempted to switch. And I'd be more than willing to beta test anything Bob may feel like cooking up in that regard.
SD1 Military
I am primarily a Cave and Wreck diver and I can't remember the last time I dove a single tank, and more often than not I have a deco bottle or a stage and deco bottle along as well. So I have a strong bias toward large stiff bladed fins like the Scubapro XL and XXL Jet Fin or, even better, the slightly stiffer and equally large XXL OMS Slipstream - a monoprone clone of the Jet Fin.
I tried the original Force Fins a long time ago and I have never been overly tempted to buy a pair. But since Bob was kind enough to let me demo his personal fins and shipped them 3000 miles to the east coast, I figured I would give them an honest try.
I did a normal dive at the local quarry in my Fusion dry suit, Evo 3 boots, doubles and a deco bottle and used them in the same manner I would in a normal cave dive (frog kicks, back kicks, very limited modified flutter kicks, etc) for silt prevention. I noted several things:
1. The foot pocket is very well designed, is quite comfortable even with wide feet and large boots and will fit just about anything. There are a couple straps across the arch, but 10 seconds of thought on the matter is all that is needed to figure out how to tuck them away (I chose to fold the loose ends back underneath the upper velcro flap, which worked quite well.
2. They frog kicked much better than I expected. They track well through the water but do feel different (more on that later). They do not have the brute accelleration or the top end speed you get with a large stiff fin like the OMS Slipstream or XL Jet Fin in a set of doubles, but they did a respectable job with very little muscle required. Not the fastest car on the track, but very efficient.
3. They were very easy to back kick in. Much to my surprise they backed up easier than any fin I have ever used - much like back kicking in a pool with no fins at all, no intuition or practice required - it just happens. Again, they were not real fast, but very easy and with minimal muscle required even with doubles and a deco bottle.
4. Helicopter turns go reasonably well, but lack the precise feel of a Jet Fin during that evolution. Not bad though and much better than I exepcted.
5. Flutter kicks were also lacking in brute accelleration and power compared to a Jet Fin, but they are a big improvement over the original Force Fins when you have lots of mass to move in the water, and again they seem to require very little muscle power.
6. They are different though and they apparently use some different muscle groups, at least when primarily frog kicking as 20 minutes into the dive the muscles in the upper outsides of my thighs were starting to "feel the burn" so to speak. This was a bit of a surpise given that my legs are quite happy and complaint free after propelling me on 2 hour cave dives in Jets and Slipstreams. I expect over time, your legs would adapt, but it is different and would take some adjustment.
My conclusions were:
A. They do not have the same brute power and instant accelleration I like with my Jets and Slipstreams, but then you wouldn't have to have large legs to power them either. And in applications where you do not need that much brute power (single tank wet suit diving) I can see the appeal.
B. They are better than any of the several spilt fins I have tried over the years (at least in a set of doubles) in terms of frog kicks, back kicks and even accelleration.
C. They were a lot better than I expected. They don't have enough power to seduce me away from my Jets or Slipstreams, especially in current or a high flow cave, where you sometimes need power right now and lots of it. On the other hand, if they came in a version with a significantly larger blade that would offer a little more initial snap and a little higher thrust, especially in a frog kick, I could envision myself being tempted to switch. And I'd be more than willing to beta test anything Bob may feel like cooking up in that regard.
