Submarine Titans was the first real time strategy game I owned to play, instead of playing at an internet cafe. It has the distinction of being the only RTS played fully underwater.
In the future, an asteroid strike has killed many and put the remaining humans underwater. The humans are divided between the White Sharks and the Black Octopi. An alien force called the Silicons was with the asteroid. The asteroid contains Corium, a highly radioactive element, and all three forces fight over it.
White Sharks (Powerhouse)
Black Octopi (Balanced)
The gameplay is complex but slow-paced. You juggle 4 main resources: Oxygen, Metal, Corium, and Gold. Units operate in one of 5 depth levels. Units can also be automated.
The manual! A huge romp of units and technologies and story! I love detailed manuals for games.
Try this piece of classic RTS gaming by buying a copy of Submarine Titans - PC over at Amazon and supporting Faction Calculus in the process.