Nathan,
In Canada and the U.S for that matter, certain specialty marine tools can be purchased through marine distributors (C-C, Kimpex, Land & Sea, T&H etc.) However as the others have already identified, the shop ultimately supplies them and they invariably come directly from the manufacturer. And given the monopoly they charge crazy prices. Go price out a new Verado diagnostic tool, make sure your sitting down.
Unless your ultimate goal is to also work from home and moonlight, it isn't cost effective to purchase most of these obscure tools. There will be enough specialty tools that you can purchase from Snap-On to help work on marine engines that will burn through all of your pay cheques for the first few years. Try changing the two lower plugs on 3.0L Optimax without taking the shroud off. A number of mechanics sell their stuff when they retire but again some experience will help you determine what you will be working on enough to justify specialty tools. It is a job after all and unless it is financially justifiable, the opportunity cost of your money is too great.
Good Luck, do you have a marina already lined up?
