3D strategy/action game from the late 80's. The premise is that you are in command of a prototype aircraft carrier, with the purpose of seeding islands with resource gathering bases. The problem is that there is a more advanced enemy carrier armed to the teeth colonising from the opposite end of the newly formed archipelago. Your aim is to destroy the enemy carrier or colonise all the islands.
Your carrier holds 2 different types of vehicles: MANTA aircraft and WALRUS amphibious assault craft. You travel to each island, choose what type of base to build and deploy a command centre builder from a walrus. There are 3 types of base. Resource bases mine for metals and drill for oil. Factory bases refine raw materials into the supplies you need to continue your colonisation efforts. Defense bases are placed on strategic islands, forcing the enemy to attack them before continuing.
This game was available for the IBM PC, Atari ST and Amiga (IIRC, others may have been available). I wasted many hours on this wonderful blend of strategy and action, only Elite took more time. I still have a copy of the game, with detailed manual, for DOS - it is still good for a blast now and then. (Now how many 12 year old PC games do you still play?)
Noder's note: Several years ago, I wrote to the publishers of this game and asked about licensing it, buying it or somehow obtaining the source code. I did not receive a reply.