Physical Danger
Rowing isn't exactly known for being high-risk.
However, rowers are susceptible to overuse injuries, which involve muscle or joint damage caused by repetitive trauma (source). The wrist, ribs, lower back, and knees are all areas at risk for this type of injury (source).
It's a good idea to take some precautions…unless you enjoy pain. That's totally a thing. It's okay.
Wrist injuries tend to occur during cold weather and can be mitigated by keeping hands and wrists warm during training. You could probably cut a fine figure rowing across the lake in frigid weather wearing minimal gear, but here's an idea: how about not getting a totally avoidable, season-ending injury? We like that idea. Do that, please.
Even rowers—otherwise perfect physical specimens to which nothing bad should ever happen physically, mentally, or emotionally—can benefit from stretching, stretching, and more stretching.
You might not be able to totally eliminate the risk of injury, though—73% of junior rowers in one study reported overuse injury (source), so it's fairly common. But if you work on proper mechanics (in boat and on erg) and have a training program that includes adequate warm-ups and cool downs, you'll reduce the chances of serious ouchies.