This is how it's stated in the Washington state boaters safety course.

Remember that it is unsafe and a violation to:
Load your vessel with passengers or cargo beyond its safe carrying ability or to carry passengers in an unsafe manner, taking into consideration the weather and other existing conditions at the time of operation, such as traffic or tides.
Operate a vessel equipped with a motor that is overpowered beyond the vessel's ability to be operated safely. Safe operation includes factors such as the type and construction of the vessel, your boating activity, and other conditions like the weather.
If it appears to an enforcement officer that the vessel is clearly overloaded or overpowered beyond safe operation and is in a hazardous condition, the officer may direct the operator to return to shore and correct the condition before continuing the voyage.