Decided to fit a Raymarine P319 'thru hull' transducer to my brand new 250as yesterday. Boat is on blocks while I fit it out. Wife and I spent at least an hour deliberating on where we should drill the two inch hole. After going down on to the pontoons in our marina and lifting the engine cover of a mate's older 250, we decided that we would follow suit and fit it starboard side as per the instructions and just behind the engine about seven inches from the centre line or transmission tunnel of the boat. Now came the scary bit... making a big hole in one's 70k boat. With trepidation and armed with my trusty Milwaukee 18v battery hand drill, a 2" starrett hole cutter with 5mm arbor and drill bit I went on and cut out the 2" hole.
I was totally gobsmacked to discover that the hull was single skin and only 7mm thick. I was expecting at least an inch or so or some form of foam buoyancy layer or something. On a big boat weighing over two ton and approved for 8 persons offshore, I'd have hoped for a bit better.
Is this the normal standard of modern day boats?