OP
Difference between force and jets
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The point is that a ForceFin will push itself onto your foot and propell you forward
A Jet Fin (and every other fin for that matter) will come off your foot pretty much instantly because it works on the principle of drag
obviously the any fin will only move you as much as you put into them. Just that some fins transfer your energy into forward motion differently. These differences are often significant, and do not only relate to efficiency.
A short stiff fin, such as the Jet fin, can be an excellent fin if you primarily frog kick, even though there is a very effective technique to use ForceFins in these environments (which is why John Chatterton uses them)
A more flexible fin is better for a flutter kick. The higher flexibility allows you to harness the larger muscle groups and kick from your abs and quads, vice your calves and hamstrings. This is where ForceFins excel, they have a few key features that make them so comfortable
1) Toes Free Footpocket- the placement of the foot pocket allows you to power the fins from your core, the kick starts from your abs, into your quads through your lower leg to the foot
2) Flexible blade, bends to a high angle, allowing the water to flow down the blade vice spilling off the sides
3) Upcurved blade tips - this is a dual drive feature,
a) power stroke (down)- the tips flex back maximing the surface area to move water
b) recovery (up)- the blade flexes inward to reduce the surface area and move with the water, this further reduces the load on your hamstrings and removes one of the major sources of cramps.
b) recovery (up)- the blade flexes inward to reduce the surface area and move with the water, this further reduces the load on your hamstrings and removes one of the major sources of cramps.
This brings up a different question, why do you want to frog kick? Do you actually believe that it the most efficient method to cover distance, or are you just following the spew of the "experts" on the internet. I admit, with many fins, e.g. Jets, a frog kick is easier to do, but this is because maintaining a flutter hurts, but that is not really a good reason to use a frog kick, thats a good reason to get different fins.
Then there are the people that say, I don't want to go fast, so why would I want fast fins. Well to paraphrase something that basically every fin review says; speed is a good indicator of the efficiency of a fin, as a fin that is fast, must by definition be more efficient as the diver has a fixed amount of energy (strength) to propell themselves, so speed is directly related to how efficiently the fin covents energy into thrust. At low speeds, it doesn't really matter, any fin will work.
As for control, well to quote a presenter at the DC Dive show, sorry I didn't catch his name, but his presentation was on photography, when asked, "what is the 1 thing that I can do to improve my photos?" he responded, "buy a pair of ForceFins" continueing that they will so greatly improve your ability to control your position in the water that you will stir up less silt, scare fewer fish away and let you get closer.
Bob, unless you are swimming with your hands, your fins are pushing you, you aren't pulling them.
They are not very heavy at all. They are only heavy when compared to plastic fins. They are slightly negative in salt water, with my dive boot in the fin they are neutrally buoyant. They aren't all that bulky either, take a look and form your own opinion on the bulk.
JClynes:
They are not very heavy at all. They are only heavy when compared to plastic fins. They are slightly negative in salt water, with my dive boot in the fin they are neutrally buoyant. They aren't all that bulky either, take a look and form your own opinion on the bulk.
OP
InTheDrink
Contributor
Thanks Meesier,
Course now I'm confused again. I think I'll see if I can borrow both and see how I get on. My primary driver really is to ditch my splits. I have some paddles on loan but they're too buoyant for my liking, but they're relatively short and I love the control. In terms of why the frog kick? To reframe the question, it's what is good for everything bar the flutter, which I use rarely. Most of my kicks are everything else, and all need work as they've been self taught or more likely perhaps, picked up from observing others. But I'll typically not use a flutter kick unless I'm fighting a current that I can't avoid. For whatever reason, using kicks other than the flutter use up a lot less energy for me. They also don't muck up the bottom. I will be ordering getting the Into to Tech DVD tomorrow which will hopefully help me improve further.
"they will so greatly improve your ability to control your position in the water" sounds good. Hopefully I'll be able to try both and make a decision based up experience as well as the useful advice received here.
Walter, thanks for your input too. I'll try out a pair and let you know how I get on.
Course now I'm confused again. I think I'll see if I can borrow both and see how I get on. My primary driver really is to ditch my splits. I have some paddles on loan but they're too buoyant for my liking, but they're relatively short and I love the control. In terms of why the frog kick? To reframe the question, it's what is good for everything bar the flutter, which I use rarely. Most of my kicks are everything else, and all need work as they've been self taught or more likely perhaps, picked up from observing others. But I'll typically not use a flutter kick unless I'm fighting a current that I can't avoid. For whatever reason, using kicks other than the flutter use up a lot less energy for me. They also don't muck up the bottom. I will be ordering getting the Into to Tech DVD tomorrow which will hopefully help me improve further.
"they will so greatly improve your ability to control your position in the water" sounds good. Hopefully I'll be able to try both and make a decision based up experience as well as the useful advice received here.
Walter, thanks for your input too. I'll try out a pair and let you know how I get on.
jlovold
Contributor
Well, they are kind of heavy when you are travelling, and also quite bulky in the suitcase... Except from that they are all good...
And with springstraps, they are even more negative...
Alternatives to Jetfins (Equal qualities, without being clones) is Turtlefins, OMS Slipstream, Hollis F1, and possibly the Excellerating Forcefin...
OP
InTheDrink
Contributor
jlovold - splendid, now my vista of choice expands nearly exponentially! 
I think my approach will be to play around with jet and force fins in the pool and see which suits me. As a recreational diver, my opportunity to try even the limited 4 brands/models of fin that you mention will be constrained. Believe me I would LOVE to try all the fins above you mention, I just don't think I'll have the chance.... :-(
In terms of bulk, again, it sounds like a suck and see. My current pair of fins are so massive and heavy that I find it impossible to believe any replacements could be worse.
J
I think my approach will be to play around with jet and force fins in the pool and see which suits me. As a recreational diver, my opportunity to try even the limited 4 brands/models of fin that you mention will be constrained. Believe me I would LOVE to try all the fins above you mention, I just don't think I'll have the chance.... :-(
In terms of bulk, again, it sounds like a suck and see. My current pair of fins are so massive and heavy that I find it impossible to believe any replacements could be worse.
J
try sending a message to member MarkUK, he may be able to help you try a pair of ForceFins out.
Whatever you choose, make sure you use both more than once before you decide. One quick use, doesn't let you really get a feel for either of them. My jets feel like I have manhole covers strapped to them now. They didn't at first feel. I have been diving with other fins and more than once, and got a reall good comparison. My twin jets are great, but not quite right for me. My twin jet pros are terrific, but not in hard current for me. My Mares Avanti's now don't flutter right.......See the trend here? I am now thoroughly sold and long time using my force fins. And I frog kick All the time in them.
My ability to maneuver is amazing. Yours may not be. Don't ask us. We will All tell you that our favorite one is the best. It is. For us. You find yours.
My ability to maneuver is amazing. Yours may not be. Don't ask us. We will All tell you that our favorite one is the best. It is. For us. You find yours.
ZenDiver.3D:
Excellent point. A friend of mine borrowed a pair of Jets, after a couple of months, she bought her own pair. A mutual friend, after seeing what happened, asked to borrow them. She used them a couple of months and decided she didn't really like them, so she returned them and went back to her old fins. After a couple of dives she went back to Jets. One of my students learned to dive in Jets, but she's small and not very strong, she kept complaining that the Jets were heavy and didn't like them at all. She finally bought another pair of fins and was very happy with how light they were. After a trip to the Caribbean with her new fins, she returned them and dives her Jets without complaint.
pescador775
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Meesier says:
No fin which produces forward thrust can operate on the principle of drag. That contradicts Newton's 2nd and 3rd laws of motion. However, there is the matter of cavitation. Any spearfisherman or diver who is familiar with striped bass or grouper knows the "boom" that accompanies powered accelleration. This may occur to a lesser extent with swim fins but if it does drag will result. However, a fin like the Quattro which produces 60 lbs of thrust minus five pounds of intermittant drag is fast indeed. Divers with high fitness can go fast and since each fin stroke produces more thrust, a lazy diver can "glide" with fewer strokes. On the other hand, a Force Fin (except the Excellerator) does not produce enough thrust to cause cavitation, hence less drag. There is the oft heard claim that the Force fin "pushes" itself onto the foot. This is true and is a function of the offset foot pocket and large toe hole. This arrangement creates torque which leverages the fin onto the foot and has nothing to do with thrust per se. Also, it partially disables the ability of the ankle and calf to exert force which throws more of the load onto the thigh and leg bicep. This can be a good thing for some people but it also means that the threat of cramps is transferred from the calf to the leg biceps. Actual cramping may be less frequent overall due to the lower capacity of the fin to absorb and transfer energy to the water. When cramping does occur it will likely be in muscles other than the calf. Less pain but also less performance which, as a tradeoff, may suit some people but turn off the rest.
No fin which produces forward thrust can operate on the principle of drag. That contradicts Newton's 2nd and 3rd laws of motion. However, there is the matter of cavitation. Any spearfisherman or diver who is familiar with striped bass or grouper knows the "boom" that accompanies powered accelleration. This may occur to a lesser extent with swim fins but if it does drag will result. However, a fin like the Quattro which produces 60 lbs of thrust minus five pounds of intermittant drag is fast indeed. Divers with high fitness can go fast and since each fin stroke produces more thrust, a lazy diver can "glide" with fewer strokes. On the other hand, a Force Fin (except the Excellerator) does not produce enough thrust to cause cavitation, hence less drag. There is the oft heard claim that the Force fin "pushes" itself onto the foot. This is true and is a function of the offset foot pocket and large toe hole. This arrangement creates torque which leverages the fin onto the foot and has nothing to do with thrust per se. Also, it partially disables the ability of the ankle and calf to exert force which throws more of the load onto the thigh and leg bicep. This can be a good thing for some people but it also means that the threat of cramps is transferred from the calf to the leg biceps. Actual cramping may be less frequent overall due to the lower capacity of the fin to absorb and transfer energy to the water. When cramping does occur it will likely be in muscles other than the calf. Less pain but also less performance which, as a tradeoff, may suit some people but turn off the rest.
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