When I first joined a rowing club several years ago, I was new to the sport and had a lot to learn. The membership director suggested I volunteer at an upcoming collegiate regatta. The rowing club shared a boat house with a local university crew team and they needed extra hands to run these events, so club members chipped in.
I had been a college athlete myself (D1 baseball), so I thought I'd seen everything there was to see in a locker room, but when I walked in to refresh the towels, I was greeted by a sea of erect cocks. Not only was every single member of the crew team somewhere between semi and raging hard-on, guys were openly stroking themselves to maintain it. This was something new.
The reality is, a men's rowing trou leaves zero to the imagination, so if you're going to do competitive rowing, you have to be comfortable knowing your manhood will be on display for everyone.
From what I gather, this isn't an universal practice across teams, but at least with my local university, the guys all shared a common understanding that they wanted to present themselves the best they could in front of spectators so there was no shame in rubbing that cock so you had something of notable stature to position down your leg.
I noticed throughout the day as guys were coming in and out of the boathouse, they were constantly grabbing themselves and shaking the hell out of their cocks through their trou in an attempt to self-fluff when they thought nobody was around . I'm a straight guy, but admittedly found this kinda hot.