I use Meguiars #16 wax.
We used to use it on the sponsons of our Atlantic but the RNLI gaves us some new 3M stuff.
I use the #16 on my car too.
Whatever you do don't use it on your deck or anywhere you sit or want to stand up as it makes the surface super slippy and water just beads off.
It'll be fine on your hull.
I get my stuff from here:
http://www.cleanyourcar.co.uk/wax/me...x/prod_98.html