...Then I really hate having to cut thick plastic, my fingers are covered with scars after 25 modeling years, i want this to stop.
What is softer than plastic and can be cut easely? yep, dry mastic will do.
I then proceeded to apply some coat of mastic over the outlines of the transversal parts of the boat. i flattened them with a greased wooden surface and let dry for a few hours -not to few because you will have the feeling of cutting through butter, not too long because Magic Sculp is a fairly fragile kind of mastic and breaks easely