Let me second, or third, the Alfa Wireless Adapter with a USB extension cable. It may not be the best or the most technically advanced, but it is easily done and very effective and best of all inexpensive.
The Alfa Adapter comes with a software
cd containing both the drivers and a utility program to control the adapter, see the networks nearest you (showing you both encrypted and not encrypted networks) and allowing you to select and connect to a particular network.
Alfa makes several adapters your looking for the 1000 mW (1 watt) unit not
the 2000 mW unit, for some reason it does not work as well as the smaller unit. I think the model number is AWUS036H for the 1000mW unit.
Some of the Alfas are sold with a standard 2 or 5 db antenna and the 9 db antenna, (those numbers relate to the gain the antenna is able to develop) get the one with both sizes of antennas if you can and experiment
with how well you can connect. Sometimes the higher db gain antennas are a little directional and the boats movement and antenna placement can affect how well the antenna works. Start with the smaller antenna, if it works well your done. Always have an antenna connected to the unit if it is powered up. Also, try to keep the antenna for the Alfa as far from the mast
as you can, it will interfere with the antennas ability to receive and transmit, that is why I use the backstay.
Do something to protect the unit from water
it is not waterproof. I used an exterior plastic electric
junction box, drilled a hole for the antenna to stick through the top and a second hole for the usb cable on the bottom, then siliconed around both. Liberal silicone. Snap ring on top and bottom, both go around the backstay. The top ring connects to the main halyard
and the bottom to a down haul, run it up the back stay and run the usb cable into the cabin
. You should put a drip loop in the cable to keep rain from running down the usb cable and into your computer. You should also seal up any exposed connections, that self sealing tape would work great I think, I just used silicone.
Do an internet
search for that alfa (around $35) and find the cheapest price
. You may also find the extension cables
there too. I have no connection with this product, other than the one I get on Wi-Fi. (Sorry, couldn't resist the pun).