frog kicking with fins

[Bob Evans]

Sorry with such a LATE response!
Look, I have no dog in the fight, so to speak. Use whatever you want. If you want to buy plastic paddles and a use a 40# spring to hold them to your foot, well, by all means, go for it!

I am a head guide here in Estonia. I have led 100's of dives with people from almost 30 different countries. We tour an underwater prison facility that was flooded post Soviet Union. We dive in buildings with silt and no current flow every day during peak season. In other words, we no likie "silt meisters"!

I have grown so tired of hearing, (after demonstrating all I do with my Force Fins such as do an entire dive WITHOUT any strap holding them to my feet, etc.) "Yeah, but you can't frog kick with them!!"

First of all, who says that you can't? I know that I can, but why bother?
Secondly, so what? WHY DO YOU NEED TO FROG KICK!!?? Frog kicking was invented to make up for the problems common associated with plastic boards spring-loaded on the end of your toes! Frog kicking is NOT natural, unless you are a frog. You have to LEARN to frog kick and it requires training different muscles. WHY BOTHER!?

Force Fins do naturally, what you have to compensate to do with plastic boards. I often demonstrate finning just off the bottom with my fins without kicking up silt. Why? Simple. The same reason that Force Fins STAY on your FEET WITHOUT a strap is the same reason that they don't kick up silt. The direct forward motion (reaction) is created by an equal and opposite action - propulsion (simple physics). The design of the fins sends the water straight back, not down. That is why you don't kick up silt.

Be a man, not a frog!

Mike you hit the nail on the head... Thank you. I have started to clean up Force Fin storage and amazed on how much we did in 37 years. Today I still feel we make the best fins in the World, even having sold over a million pairs, some how I had thought it would have been much more..but then their is still time. Our USA Plant rocks and I am ready to Kick assss in 2020. Found all the legal files with Rodale Press. Talk about " Fake Reporting " and they got away with it. Like Mark Twain states : Do not mess with the press, they have barrels of ink " God Bless you Mike. Bob and Susanne

 

[sibermike7]

Mike you hit the nail on the head... Thank you.

You are so welcome Bob!

Great pic! Hey if you two want to come over, we'll hook you up! We have a place where you can stay and we'll show you around!

If you run into any whiskers, let me know!

 

[M-Cameron]

Yes. There is a physiological basis for the strain experienced from flutter kicking with flat fins. Something I solved by looking at the natural kick strength of our leg first. Personally, I and most of us move more efficiently flutter kicking. Frog kicking may have taken hold in training through cave diving, but it is as much a fix, compensation for fins that work against your natural kick strength.

but is it actually more efficient?

when you look at a flutter kick:

the direction of the force(F) is going to be perpendicular to the angle of the fin....on a typical power stroke only the Fx is contributing to moving you forward, and a large portion of the energy is wasted in Fz which is translated to vertical movement.


in a frog kick.

a larger component of the force is going towards Fx (forward momentum)......and the Fy components are not only smaller, but also cancel each other out

 

[BoundForElsewhere]

so why are force fins so expensive?

 

[Bob Evans]

so why are force fins so expensive?

Good Question, it's a very long story. I will keep it simple. We use hand cast Poly-urethane which is expensive, heat treat for 16 hours at 270 degrees which gives me the snap needed to move. Plus my designs can not be made from cheap plastic, and I love American Production. try a flip test with your fins...tell's you what your fin is made from..most fins cost around $7.50 -$16.00 to make with a 400% mark up...not bad.

 

[Bob Evans]

but is it actually more efficient?

when you look at a flutter kick:
View attachment 562904
the direction of the force(F) is going to be perpendicular to the angle of the fin....on a typical power stroke only the Fx is contributing to moving you forward, and a large portion of the energy is wasted in Fz which is translated to vertical movement.


in a frog kick.
View attachment 562917

a larger component of the force is going towards Fx (forward momentum)......and the Fy components are not only smaller, but also cancel each other out

I am confused, nice drawing,

 

[BoundForElsewhere]

all good reasons. thanks, Bob.

 

[Bob Evans]

Kick how ever you like. Force Fin still holds the World Record...

 

[Jcp2]

An effective Force Fin flutter kick is closer to what might be considered by others to be a modified flutter kick. The thigh is relatively straight and moves only a little bit, with the main pivot point being the knees and the main motivating muscle being the quads. It's nothing like a full amplitude freedive flutter kick with long fins, and not much like a swimmer's flutter kick, with the leg being relatively straight and all the drive coming from the hip flexors.

 

[Bob Evans]

Commander Clark Presswood did it ok.