Hello, Maryam,
Thank for the plan, it makes you situation much more clear.
Actually, the most important question is where you can mount APs (and have power + LAN to them).
You obviously have many options. You probably want to mount all APs on land, which will be easier and more reliable.
It seems more appropriate to use APs with directional antennas (T301S (120x30 degrees) and T301N (30x30 degrees).
If you can use building roofs, than you can cover all boats (and most of marina) by 3x T301N + 1x T301S APs, located somewhere on building roofs 4, 3, 2, 1, and providing good speeds and minimal interference.
If you want even better coverage, you can just use 6x T301N (one per pear).
If you are limited in AP q-ty, you can actually install just 2x T301N on building 17, and 1x T301S on building 13, with proper APs orientations you'll get very reasonable reception in most marina.
In any case both vertical and horizontal angles must be carefully calculated in accordance with AP mounting height and necessary coverage sector borders.
You can use downtilt to limit reach of APs in the last case.
There is a lot downtilt calulaltors available in Internet, which will give you start and end of -3db level reception zone, if you put in antenna diagram width (30 degrees), AP location height and downtilt (say, 10 degrees). So you can easy calculate what downtilt you need with which mounting height.
If you are limited to APs with omnidirectional antennas (T300, for example), than you need to mount APs somewhere in the middle of area. This will work, but is less attractive option (you'll probably need to use mesh connections instead of copper cables, because of distances, for example). It will work too, of cause. But you'll need some 7-8 APs for good coverage, and then you'll have more interference.