Physical Danger
Listen up, boys. You got most of your body underwater—vulnerable, unprotected, and crashing against other dudes. Then, you got a terrifying amount of kicking and paddling. You do the math. You're going to get kicked in places you don't want to get kicked.
Ladies, count your blessings (in this case, there are two).
Before each game, the referees are required to check for knives in your swimsuit and for sharp fingernails. Same deal with the toenails. Biting, if caught, is frowned upon, as is punching, kicking, clawing, gouging, gorging, shanking, impaling, and any other kind of physical abuse one could do, mano a mano.
Sound brutal? That's because it is.
Water polo is openly not nice. There's a shared commiseration and brother/sisterhood of backs scratched so violently that they bleed and bruises that don't go away until the off-season. Black eyes mesh beautifully with red ones, courtesy of elbows and chlorine. Shots on goal regularly exceed 60 MPH at the top ranks and 40 in high school. If you want to know much it hurts, roll down your window next time you’re on an expressway and have the guy in front of you throw a package of meat at your head. Let us know how that goes.*
It's not uncommon for an athlete to take a shot to the head or face, from either the ball or another player. Broken noses, scratched eyeballs, perforated eardrums, and concussions definitely happen, all of which can be super dangerous because, well, you're in a pool and could drown if you're unable to swim (source). So, yeah, preventative care is crucial.
Many serious water polo injuries, however, are actually non-contact. Because of the heavy stress that the sport requires of your joints, especially shoulders and knees, they will often rebel. And you can't blame them. Usually, you stay safe by listening to your trainers as if they're somewhere between Gandhi and the Dalai Llama. Junk food? Not your friend. A buff body? Your friend. Water polo requires an incredible amount of fitness and stamina and you have to be able to put in the reps if you want to make it as a college athlete (source).
*Don’t really do this. Shmoop admits no liability for Shmoopers that have meat thrown at their faces at speeds higher than 20 MPH.