vash, You mentioned running. Good read about breathing rhythm and swimming.
Breathing right will put you on your way to swimming right | ACTIVE
Anyways, I'm curious of a fellow I observed last year at the pool. Darned if I didn't ask about his technique but maybe someone here can pipe in.
He would stay at the surface but his head fully submerged, except the back and apparently lungs were exaggerated arched, sort of like a hunched back. Super slow forward movement but easily swim the length of pool. Its as if he was breathing under water, but as mentioned his back was hunched and out of the water. Estimating five + minutes! Bizarre. Must be years of muscle discipline and calmness?