Suit ID

[Swimmboy]

It's possible the black armband was a sign of solidarity for a swim team that was being abolished. A large university near me abolished its swim team two years ago, and during their last year of competition, many of the opposing teams wore such armbands as a sign of mourning for the loss of a rival team.

[midlifeswimmer]

The square logo might well be Hard Core Sport. https://hxcsport.com
They make "narrow" and "mid" cuts, this looks like narrow.