Originally Posted by rockDAWG
I was thinking to rely on the GPS and chartplotter that come with the boat
I wouldn't trust that too much, the GPS on the boat I rented was an antique, and didn't have a chart plotter. It only gave your speed, heading, and coordinates.
I would strongly suggest you bring a handheld unit pre-loaded with the correct charts, that you are familiar with it's operation before you go.
That said, the only time we actually turned on our handheld was the passage from Virgin Gorda to Anegada, and back. That was just to keep track of our course over ground to ensure got to the entrance to the harbor without finding the edge of the reef. The rest of the time we simple did visual navigation, with a touch of dead reckoning thrown in. We never used the GPS built in to the boat.
bringing a GPS unit you are comfortable with and familiar with it's operation is important as a piece of safety equipment, but should not be your sole navigation tool.