I just installed a Wirie AP last week, mounted on the stern pulpit, this one has a hotspot built in so you just need a 12 volt connection, not USB, then you have your own wireless network on the boat.
I've only tried it in the marina but before I could only see 5 networks and none were strong enough to connect. Now there's hundreds but I just connected to the nearby Marina Inn.
Install was comparatively easy, just run the power cable thru transom and up to the panel with a 2 amp fuse.
You could put one together yourself no doubt, but when I started pricing out components it didn't seem too bad.
"Just call me TB"