is the boat 21.5' or is the trailer that long. If it's the trailer, just get a swing away tongue. Otherwise unless you can build a small extension out the back you are stuck with parking it kitty corner taking up 2 stalls
Interesting, my trailer's tongue swings right at the nose of the boat and the boat hangs off the back of the trailer a bit. The trailer doesn't add any length to the trailer/boat combo.
A friend of mine has a 23' malibu w/ a 21' garage. he blew out the back section of the garage and put a 10x10 storage shed against it. He removed the doors and sealed it to the outside wall. Now his swim platform and the back part of the boat are inside the shed.It looks pretty trick for minimal $$
The swimdeck usually isn't included in the boat length, the only way to park it in a single stall is to see if you can extend the garage a couple feet on teh front side. Will be quite expensive, honestly you'd be better off trying to find a house with a deeper garage if it is important to you to have a car and boat in the garage at the same time