Point-to-point network for sailing vessels

This is a bit of an odd one.

I'm in the process of researching some wireless equipment for two sailing boats that will need to be able to communicate with each other (think lead and follow boat). One of the boats will have a satellite uplink (follow boat), and the intent is to provide a wireless hop to the other boat (lead) for connectivity.

Ideally they are asking for a solution that will provide connectivity in a 5 mile range between the two boats without having to aim the antenna. This is kind of the major block that I've run into, as omnidirectional antennas become limited in coverage without boosting power up like nuts. I understand that their expectations in this regard may be unrealistic, but I'm still putting it out there in case there's some workable solution.

Additionally, the access points need DC power. I've found some POEs that will support 802.11af with DC power, so I think I'm OK there.

Currently I'm looking at getting two Ruckus T310d units, which have built in ominidirectional antennas. However, they appear to only offer about a half mile of coverage, which is a pain point. Other similar outdoor-rated access points from Engenius are also on my list at the moment.

The limitation is that these are 60 foot sailing vessels, so they're not big. I can probably put an antenna at the top of one of the masts for better coverage.

I appreciate any input on the Ruckus units or alternative options, or places to do additional research. I have good familiarity with wireless tech and its capabilities, I'm just rusty on what equipment is out there and available.