Where in Cape Coral are you putting that??

My garage is 48' deep. Just right for my 32' with a little room to spare on the ends. Takes the full 8' tall door to get'r in, so I am limited to the size and make of the boat just do to the door height. A couple buddies have a 34PQ and 35 Cig, they need 9' doors to enter. The door height will be your biggest obsticle for an attached garage.

Mine is 50' long. If I want to work on my 42' Harley I must open the door and pull it out a few feet. Works O.K. for storage.

it is in ny

My garage is 48' widex105' long big enough for the boat, race car ,race car trailer, gator, two John Deere tractors, one Monte Carlo show car and another Monte Carlo in off frame restoration right now. This leave me enough room to still wash the pull truck when it gets dirty. Oh I forgot it also has a office with a full wet bar and a full bath plus satellite TV all air condition when it gets hot outside. Plus a couch when you get tried from working on everything so you can lay down and take a nap. The old saying goes " The guy with the most TOYS wins"

If you have the room .........it's cheaper to do it now than add on later.
GO BIG.....

A good rule of thumb is the garage needs to be at least 12' longer than the boat you want to store in it. A 36' boat with a Trailer with Drive guards will just fit in a 48' stall, if you want room to work around it you will need more length.

That said Bigger is better.

Depth and door height are the two major concerns with a boat. When I first built my garage 15 years ago with 42' depth and 10' doors I had plenty of room for my 26' Mirage. I bought a 35' 8" Sonic last year and I had to put a 2' telescoping tongue on the trailer in order to have room enough to walk around the boat. The 10' doors only leave about 1' of height clearance. If you need the extra depth or contemplate needing the extra depth for boat length, design the garage where you would have a stall in the garage with additional depth. I f you design it right you could build it that way now or add the extra depth later.

My front door is 16x9 and i had to take the radar arch off also to get it in there.make sure you go wide enough to start because if you add on later its easier to buy the same size trusses and just go back

Figure out what you truely need......then double it - then you'll be fine.