Final answer:
One method to help free yourself if grounded aboard a small powerboat is to jump clear of the boat when a wave comes piling into it.
Step-by-step explanation:
If grounded aboard a small powerboat, one method to help free yourself is to jump clear of the boat when a wave comes piling into the boat.
By doing so, you can avoid getting trapped inside the boat and increase your chances of swimming to safety. It's important to have a plan and communicate with others in the boat to ensure everyone is aware of the escape strategy.