If the boat has been setting awhile, hook a hose to it in the driveway or stick it in a garbage can full of water at home and make sure it starts, runs, etc. Waiting at the ramp while someone can't get it started is a real downer. If it does not start, pull it up in the lot to change plugs, drain gas, etc. I have watched guys at the ramp almost dismantle a motor while blocking the ramp. Like the guy above said, be prepared.

How many boats have you seen watched (or done yourself as I have) without putting in the plug? Basic boating 101 but everyone does it sooner or later.