Start with one of these http://www.harborfreight.com/air-ang...der-32046.html with a cut off wheel. Think twice and cut once.....carefully. :) Then level it out with the hull.

Thanks don,

I'll give the die grinder a shot when I'm ready to dig into it.

Gotta get some electronics! Those Airmar Xducers sure are looking good the more I read about them.