Buying
The things that decide what a waterfront lot is worth are mostly invisible
You can walk a property, love the house, and miss every one of the things that will matter to you in five years.
Here is an example
A seawall in serious trouble often looks fine. Hairline cracking in the face, a hairline in the cap, small divots in the yard where the panels meet — to most eyes that is a well-kept wall. To someone who has seen a few fail, it is a six-figure repair that has not announced itself yet.
That is the kind of thing you want identified before you write an offer, not during the inspection period when the leverage has already moved.
Here is another
Most people buy more boat over time, not less. Almost nobody goes the other way.
So the question is not what fits today. It is whether you will be able to keep what you will want in eight years, given the seawall you have and the canal you are on. A 65-foot canal and an 80-foot canal look identical in a listing. They are not the same product, and one of them will not turn a fifty-foot boat.
And that is before lot position, water depth at your seawall, overhead clearance, and how long the run to open water actually takes in the boat you will be running.