The marina charge you for the space you actually take up, not the length of the hull alone. I managed Dry Stack marinas for years, and if somebody comes in and tells me their boat is 23', and I stick it into a rack that is 24' deep, and the bracket and motor stick 3 feet out into the aisle when the boat is shoved in all the way to the back wall, I'm going to charge him for 27'. The portion of the boat sticking out into the aisle becomes a hazard, and is much more susceptible to "hanger rash", being hit by the lift as it moves other boats around. You pay for the vessel's true LOA, not the listed hull length.
As I told one customer with a 26' Searay Sundancer with long pulpit and swim platform with an actual LOA of 31'4",
"If you only want to pay for 26' of boat, we'd be happy to cut either the bow or stern off at exactly 26' LOA." 
__________________
Common Sense is learning from your mistakes. Wisdom is learning from the other guy's mistakes.
Fr. Frank says:
Jesus liked fishing, too. He even walked on water to get to the boat!
Currently without a SeaCraft 
(2) Pompano 12' fishing kayaks
'73 Cobia 18' prototype "Casting Skiff", 70hp Mercury