|Alfa Marine USB Wi-Fi|
The pictured module has an integrated 12 dBi long-range antenna. Although the antenna is directional, the pattern is wide enough that pointing is not critical, and a fair amount of boat movement is tolerated. With clear line-of-sight and a good antenna at the other end, range can be a mile or more.
Available on Amazon for only $35 (link) as of this writing. Drivers provided for Windows, Mac OS, and Linux.
(Beware of cheaper off-brand units with exaggerated claims of antenna gain or range. Most are junk.)
Tip: Only one computer is supported, but if the computer has Wi-Fi, software can turn that Wi-Fi into a hotspot for wireless devices. Sharing over Ethernet (cable) is also possible.