The movie is swimming in positive messages about the importance of family and friends, the bond that exists between human and animals, and the idea that being disabled doesn't mean that you can't accomplish your dreams. Curiosity, empathy, and integrity are major themes.
When viewers first meet Winter, she's lying on the sand with rope tied around her tail and body, and her tail fin is bloody and bruised. When she eventually has to have her tail amputated, she's shown in the water with the remaining stump; Sawyer and Hazel are very upset. Sawyer's cousin returns from his deployment in a wheelchair, but his injury isn't described or discussed in detail. A hurricane hits Florida and destroys parts of the sanctuary, but no animals are shown hurt.
A mildly flirtatious first meeting between two adult characters, plus some brief shots of shirtless and swimsuit-wearing teens at a pool party.
"Crappy," "holy smokes," "shoot," and "stupid" are as strong as it gets.
Brief mentions/shots of a Nintendo DS, Swiss Army knife, and Wikipedia.