Don't confuse power washers with pressure washers
A true pressure washer puts out 15,000 or higher psi...and I agree that using one to clean a boat is highly risky. A 1000-1600 psi power washer is only about 2-3x that of a garden hose nozzle...not enough to put gelcoat at much risk unless you put the nozzle right against and stand there for 5 minutes. And they're one of the handiest gizmos you can own...among other uses, they force bilge cleaner and water into places in the bilge you can't reach. They're also great for hosing down the dock finger, which cuts down on the amount dirt tracked aboard...cut spring boat cleaning time in half. And they're VERY handy for cleaning vinyl cushions...not to mention decks, patios, patio furniture, grills, sidewalks and driveways at home.