If you repaint the bottom, make sure the bottom paint is copper free!
If you do your own electrical work, be careful when you're stripping
wire. Don't leave those little metal strands in the bilge.
Don't use the hull as a ground for 12 volt equipment.
I think some people use a metal other than zinc as a sacrificail metal
for an aluminum boat in fresh water.
Make sure you always shut off your battery switch when it's not in use.

John