Not automatically. A waiver does not automatically answer every liability question. Its effect depends on its language, the applicable law, and what caused the accident.
Rental cases are a good example. A rental company might provide poorly maintained equipment or inadequate operating instructions, and another boater could also contribute to the same collision. Rental company conduct may still require careful investigation.
One conversation is enough to know where you stand. It costs nothing, and you will speak with Brandyn.