Marine Units

Lvl 1 Shipyard
Delta (Light Assault Amphibian - Can go on land-Can disable mines)

Lvl 2 Shipyard
Viking (Heavy Destroyer, can detect submarines) where I can unlock it

Lvl 3 Shipyard
Poseidon (Heavy Missile Battle-cruiser)

Lvl 1 Shipyard
Caiman (Light Recon Boat (Minelayer))

Lvl 2 Shipyard
Alligator (Heavy Corvette)

Lvl 3 Shipyard
Barracuda ( Missile-Torpedo Submarine)