I have sprayed some of both on various trucks and equipment. I have my 29 Scarab stripped down to the white hull and think I might want to now put some graphics on it. I don't plan to paint the white gel because its in good shape. The graphics would be under the rubrail and to the water line in the back. Should I use base/clear (if so I assume I can just clear the graphics and it will be ok) or should I go with a single stage?

Forgot to add that if I do it there will be probably 4 colors

Without a doubt bc/cc would be the easiest to work with. Depending on how old it is pinholes in the gel could be an issue. Also clear about 1/4 inch past the basecoat.

thanks I was hoping I could use base/clear but wasn't sure how much to clear past the color.
Also can I scuff and paint or do I need a sealer. Everything I have painted up to this point always gets epoxy primed.

you need to use a sealer, epoxy sealer would be fine.