Where is the greatest resistance?

during swimming? Completely underwater, or half underwater (water surface)? Ask breaststroke specialists. They are the one having to constantly face this dilemma. I'm far from being a breaststroke specialist, but as a well informed observer, I think that the depth prescription for breaststrokers have changed over years. Not sure where it stands right now (and I don't really care). Pushing off the walls and after the dive, we've known pretty much forever that you have to go little deeper than the surface in order to get more velocity. Phelps (among others) has pushed this principle to a new extent by literally diving deeper after each push off.

during swimming? Completely underwater, or half underwater (water surface)? Ask breaststroke specialists. They are the one having to constantly face this dilemma. I'm far from being a breaststroke specialist, but as a well informed observer, I think that the depth prescription for breaststrokers have changed over years. Not sure where it stands right now (and I don't really care). Pushing off the walls and after the dive, we've known pretty much forever that you have to go little deeper than the surface in order to get more velocity. Phelps (among others) has pushed this principle to a new extent by literally diving deeper after each push off.