I have a unit called ALFA which I got on-line from Allied Data for $65. It is an antenna, coax to card (3x2x1/4),usb to laptop usb.The CD has drivers for Windows and Mac, the range is at least 1/2mile (line of sight) and it is Omni. I hoist the antenna on the backstay and keep the card in the saloon, it dont seem to make a difference how high the antenna is however it will drop its single from time to time. Retuning takes seconds and away we go again for days. All the people who have seen the unit working have got themselves one. Free WiFi is the norm here in Florida, houses are large and most have routers so they can get on-line at the pool etc.Give it a look , all the best. Peter