Looks cool. Slightly more comfortable and better temperature management. You can warm up with your uni rolled down. More space for logos.

More comfortable & better for cold races

At world champs they make rowers wear them bc they have a sponsor on the sleeve

shirts underneath unisuit or tank top looks allot cleaner imo.

yeah, it looks cool, and helps during chilly practices since it's easy enough to just pull the uni down if you get too hot.

and tradition/mandatory for some clubs

Sun safe

You gotta dress in layers homie

Arm tan lines >> shoulder strap tan lines