I shall follow this thread with extra interest because I have been breathing to the right for 60 years and one of my goals for this winter in the pool is to breath easily to the left. I can do it in the pool but in open water I soon get out of time and backslide to the right. I have no trouble holding course breathing unilaterally and often swim 50 strokes before checking but some sea conditions make breathing tricky.
What finally convinced me that I had to make the effort was a swim in the estuary this autumn. I arrived at the water and realised I'd left my yellow cap and smoked goggles elsewhere. I swam anyway but on the way back the low midday sun was full face. I had a bright golden globe in my eyes for the rest of the afternoon.