There are loads of options making a PtP (point to point) wifi
connection. There are also thousands of different things you need to address to get a proper wifi connection to shore.
Will the ship be moving around? Is there L.O.S (line of sight) with the accespoint ashore? How much distance needs to be covered? Do you setup your own shore based AP, or is it to connect to an existing AP?
My personal experience is that wifi connections are a lot less stable then a 3G (mifi) connection. Or at least the need a lot more attention before they work properly. F.I. A ship moving around on a mooring/anchor is quite a hand full to keep a 100% working wifi connection, especially on a longer distance.
-Now when I would connect two points with a static location I would choose 2 NanoStation5's but that would work great when there is no movement. specs
-One static location and one moving would be one NanoStationM5 (or 2 to cover 120 degrees) and one picostationM5 on the moving object. specs
Note that the 5GHz is *only* an option when you have L.O.S. if not 100% L.O.S. make sure you choose the 2.4GHz ( NanoStationM2 PicoStationM2) 5GHz is a lot less crowded then the 2.4GHz, eliminating a lot of noise
These setups are quite affordable and will get you a high performance wifi connection.
(200$ on hardware
I would guestimate.)
Again, if you want to know more you need to supply us with a LOT more information.