[deep6]

There is a very cool way to use the iPad on the boat, get a serial to tcpip box, hook it up to your serial buss that has all your data on it, config the tcpip to some flat network "super easy, one sub net 192.168.1.xxx". Hook that up to some beater cheep wifi unit that has a configurable DHCP address range, name the ssid, point the iPad to it, and use iNavX. You now have a wireless instrument any place on the boat.

http://www.moxa.com/product/NPort_5210.htm