Ah funny...never thought that was for a boat!:)
I had believed that will be for engrave something with letters!
So i will start for build an inversed boat's hull for have any form of engraving! :)

A boat floor deck is totally other thing!
I am not sure that the deck is longitudinally curvated!
It's generally flat! Flat inclined or domed laterally for evacuate water! ;)