I've had the good fortune to sails with folks of both major political opinions. Strongly held beliefs. Implacable, even.
95% or 99% of the time we are busy talking about sailing while on the boat. Politics (and sports) are distractions from racing. I've snapped at teammates to "talk about the next wind, not the Yankees" while on the rail. Can't remember anyone talking Trump or Obama or any politics on the rail.
My teammates who know my beliefs might well make fun of me back on land -- and it's just fun, because why get into a disagreement? I'm not going to change their minds, t