Looking at the helmets that I see sea kayakers wear when in and around rock gardens, or doing roll practice, would my Bell mtn bike helmet, that also has a visor, work just as well, maybe even more so since its much more vented for comfort and drainage??
I use a Nutcase skate helmet for whitewater rafting. Nutcase makes water helmets, but the skate ones have the adjustment dial in the back that fine tunes the fit to your head. I think there are differences in the type of foam used in the helmets to achieve a safety rating certification for that sport. I’m not sure there’s a huge difference in protection, but the ability to withstand repeated blows varies with the type of foam. For what it’s worth, I like my Nutcase. It fits well so therefore I wear it voluntarily.
I’m no expert on helmets but I’ve been biking a long time. Bike helmets are pretty much ‘one-hard-crash-and-replace’ items. I’m betting that helmets designed for whitewater are designed to take repeated hard hits. No. I wouldn’t do it.