A 29’ boat isn’t going to have a 29’ liveable area.
First off, a boat narrows so much at the front that a 29’ boat is really closer to 25’ at best. Then it might be 10 feet wide, so you’re looking at about 250 square feet. Most of that is gonna be deck so cut that in half again if you want your living space to be out of the elements.
When you go under the deck you might think there would be plenty of room, but you need to have fuel, engine, generator, bilge, etc.
So in your remaining closet-sized space you need to be able to eat, sleep, cook, use the restroom, store your shit, entertain yourself, etc.