Depends on what you want to do. Some tedious tasks can be automated if you know how to code, but there are already some tools available that can be used for basic and more advanced stuff (like mine, see sig., also see one of the stickies for more mod tools). No need to reinvent the wheel. I suggest you first browse/search the boards first for info, and start by picking apart existing mods to get an idea of what can be done. Creating a new boat is not really all too easy yet, so you may want to start small first. Then again, never hurts to set a challenge...
[edit] lol, basically I could've just said, 'what Ducimus said!'