OK, subterranean WiFi is cool, but what about subaqueous connectivity? If you're in the depths eye-to-eye with a colossal squid through the portal, it's kind of a drag if you can't post that pic to Instagram. But remember that WiFi is essentially a radio signal, and unfortunately, radio signals fail underwater. Fear not! A sub-aquatic internet firm (yes, there is such a thing) named Subnero is busy working out the details of an alternative plan somewhere in Singapore.
It works as follows: Subnero installs nodes underwater at intervals of several miles (kilometers). The node network sends and receives signals from surface buoys that, in turn, communicate with satellites or cell services. Your sub can then send out sound pulses to the internet via the nodes and buoys.
There are just a few little glitches to work out like, for instance, the fact that sound travels through water 100,000 times more slowly than radio waves travel through air. Not exactly broadband speeds! But Subnero carries on undeterred, convinced that the solutions are just around the corner. In the near future they're hoping undersea WiFi will help pull off all kinds of tricks, such as piloting aquatic drones or augmenting reality for divers [source: Kingsley].