I would be wary, but wouldn't say to never use a power washer. I would take care to avoid the seams, etc, and even more careful to keep the nozzle on a wide fan, rather than a pencil point. I've literally seen auto paint stripped off a car where somebody got up close with the focused stream. I could definitely envision material tearing apart or delaminating if you're not real careful.
With some of the boat cleaner, or even a bucket with dish soap and warm water, and a green scrubby pad, it shouldn't take a whole navy to get her all cleaned up. I would be surprised if it took you more than an afternoon all on your own to git-er-done.