I know this is an old thread, but I'm guessing it might get resurrected as more Signal K apps appear. For that reason I'm adding a little info...journey on":1x443hqx said:
Signal K does not mandate a wireless link. It converts NMEA data to the HTML language, which is what websites speak. Today the most common way to access websites is via Wi-Fi, but remember those little RJ-45 Ethernet connectors? That's how iKommunicate delivers Signal K. It does not make it available via Wi-Fi. For that you have to also purchase the iKonnect box. This combination is an off-the-shelf solution for non-Arduino/Pi/whatever hackers.
So if you have a laptop with an RJ45 Ethernet jack you are set to go without implementing Wi-Fi. If you want to connect the iKommunicate to an iPad without Wi-Fi, then buy a Lighting to Ethernet adapter for $20.
If you want the convenience of Wi-Fi and you want to ensure that nearby boats can't read your NMEA then secure your network with a password. Properly implemented Wi-Fi security today will repel all but the NSA, and maybe them too - who knows!