Gambitious Digital Entertainment announces plans to publish Diluvion this fall. This is a deep sea submarine adventure in the works at Arachnid Games for Windows and OS X. They describe their influences being the works of Jules Verne layered with ship-to-ship combat inspired by games like Wing Commander and Freelancer. This trailer offers a look and there are screenshots and details on the game's Steam page. Here's the plan:

After a great flood devastates the world and its civilizations, humanity’s last remnants are left to struggle against each other for limited resources and survival beneath an impenetrable layer of permanent ice. As submersible captains, players must explore the uncharted reaches of the open sea, brimming with distinct harbors, factions, mercenaries and secrets. Salvage treasure and supplies from wherever possible, trade goods and bounties, battle enemy vessels in real-time 3D action and take on gargantuan creatures from the darkest depths of this beautifully realized aquatic realm.

Managing the nine uniquely equipped submarines available is a central challenge of Diluvion’s thoughtful and gripping gameplay. Players can recruit officers of varying skill sets and personalities from ports around the sea to helm the different battle stations of their vessels. Ships can be enhanced with new weapons to change the tide of a firefight, as well as new components to increase their range and survivability. Captains can even build and upgrade their own home bases of operation beneath the ice to house stand-by crew members and subs while increasing their notoriety and wealth.