Efficiency evidence: frog vs flutter?

[undrwater]

Out in the open water, silt up is not a concern. If you are in open water and swim very slow most of the time, does the type of kick and fins really matter much ?

On muck dives, yes. And even if you're traveling over sand, there are critters beneath that can become disturbed (I've seen it). Fins or techniques that minimize silting are useful in many environments.

 

[ReefHound]

Out in the open water, silt up is not a concern. If you are in open water and swim very slow most of the time, does the type of kick and fins really matter much ?.

I've also found the frog kick to be useful when leading dives to make sure you don't outrun the ducklings. Due to better trim, style, and streamlining even a slow flutter by an experience DM might be tough for them to match.

 

[dmaziuk]

The other issue with the frog kick is that you get to the energy advantage of the glide between kicks.

You kill a lot of it in the recovery phase when the blade has to go against the flow and act as a brake. The glide feels great but in reality large part of the feeling is the contrast between fastest and slowest parts of the kick cycle. It's really bad in the "breaststroke proper", perhaps less so in the modified frog kick in fins. If you manage to turn the fins "edge-on" all the time.

 

[ronscuba]

On muck dives, yes. And even if you're traveling over sand, there are critters beneath that can become disturbed (I've seen it). Fins or techniques that minimize silting are useful in many environments.

Yes. When I wrote open water not being a silt concern that meant open water not close to the bottom.

For some reason you only quoted part of my post. The sentence directly previous to what you quoted mentions frog kicks are good for being near the bottom.

"I agree on the biggest advantage for the frog kick is to minimize silt up. Perfect for cave, wreck or if you are near the bottom."

 

[MargaritaMike]

I am wondering if when the flutter kick is being referenced it is really the scissor kick that is being discussed. I use a flutter kick on a swim-thru, however, if it is done incorrectly it can silt up the water.
Out in open water I use both the frog kick and the scissor kick. Maybe I have bad technique but it seems to work for me. When drifting I will use the flutter kick for stability sometimes. Again, probably poor technique. It just occurred to me that may be the reason I hang back when diving with a group - so no one can see my bad technique.
- MM

 

[MichaelMc]

For open water moseying along, I find frog kick more 'efficient' in that it leaves my body stable and calm left to right, whereas a slow flutter rocks me back and forth and is not nearly as tranquil and quiet. I prefer a gentle push glide rhythm to a constant left right roll from the alternating torques of a slow flutter.

 

[RyanT]

You kill a lot of it in the recovery phase when the blade has to go against the flow and act as a brake. The glide feels great but in reality large part of the feeling is the contrast between fastest and slowest parts of the kick cycle. It's really bad in the "breaststroke proper", perhaps less so in the modified frog kick in fins. If you manage to turn the fins "edge-on" all the time.

I'm certainly no expert in biomechanics, but for me, I actually do a full glide. After my power stroke, I actually just relax my legs for a moment and don't move them at all as I'm moving forward, once I begin to come to a stop, I do another power stroke.

 

[ronscuba]

A proper flutter kick has minimal knee bend with toes pointed on both up kick and down kick. Sounds like what you are calling a scissor kick.

 

[ReefHound]

I'm certainly no expert in biomechanics, but for me, I actually do a full glide. After my power stroke, I actually just relax my legs for a moment and don't move them at all as I'm moving forward, once I begin to come to a stop, I do another power stroke.

I am a big fan of the frog kick but I don't buy into this "glide" saving energy, if anything it is a net negative. Changing inertia and regaining speed is more expensive than maintaining it. Think of it this way, do you get your best fuel economy on the freeway by maintaining a constant 70mph or do you accelerate to 70, coast aka "glide" down to 50, accelerate back to 70, coast to 50, repeat over and over?

 

[RyanT]

I am a big fan of the frog kick but I don't buy into this "glide" saving energy, if anything it is a net negative. Changing inertia and regaining speed is more expensive than maintaining it. Think of it this way, do you get your best fuel economy on the freeway by maintaining a constant 70mph or do you accelerate to 70, coast aka "glide" down to 50, accelerate back to 70, coast to 50, repeat over and over?

Good point ReefHound, however, human muscles working in discrete power strokes work quite differently than ICEs do. Human muscles harness energy from either aerobic or aerobic metabolism, not the single fuel source as ICEs do.. The more rest in between human power consumption (strokes), the greater efficiency from aerobic performance and the longer it takes to get to the point of inefficient anaerobic metabolism. Further, I agree, if you are trying to cover a lot of ground quickly, then you are likely to experience some loss of efficiency by the energy input required for acceleration back to your original speed. On the other hand, if you are kicking along with consistent muscle force on each power stroke (and not in a hurry), then your overall muscle output remains relatively low. If I need to get somewhere fast, then I kick at a constant rate, or better yet, pull with my arms and harness much smaller muscle groups.