I'm pretty sure the greatest resistance is on the surface. Just from an energy balance, if you're right on the surface and you're making waves, it takes energy to do that. There is energy in the wake.
If you're far enough under water where you don't interact with the free surface, all of your energy can go into forward motion. If you're not Michael Phelps and you don't have enough lung capacity to go four feet down for 15 meters every turn (wow!) dolphin kicking on your side is more efficient because you won't interact with the surface as much. Illegal in backstroke, you can't be past 90 degrees, so you'll need to go deep to get the most out of the kick.
I've been working on SDK, though I still don't go deep enough. When I do hit the turn right, I can tell the difference and it feels faster, but it takes more lung capacity than I have to do it every turn, all the time.
I'm pretty sure the greatest resistance is on the surface. Just from an energy balance, if you're right on the surface and you're making waves, it takes energy to do that. There is energy in the wake.
If you're far enough under water where you don't interact with the free surface, all of your energy can go into forward motion. If you're not Michael Phelps and you don't have enough lung capacity to go four feet down for 15 meters every turn (wow!) dolphin kicking on your side is more efficient because you won't interact with the surface as much. Illegal in backstroke, you can't be past 90 degrees, so you'll need to go deep to get the most out of the kick.
I've been working on SDK, though I still don't go deep enough. When I do hit the turn right, I can tell the difference and it feels faster, but it takes more lung capacity than I have to do it every turn, all the time.
