Aquazone / Aquanauts

Aquanauts was the first subtheme in the Aquazone theme from 1995 to 1996. The story consisted of the Aquanaut miners, a group of miners based at the Neptune Discovery Lab, fighting against the villainous Aquasharks and their leader Thresher for control of the crystal mines. The first generation of sets consisted of a yellow base color to the subs which gave the Aquanauts a more realistic appearance to real submarines.

Aquazone was an underwater theme introduced by LEGO in 1995 that lasted until 1999 and contained five subthemes all of which took place in the ocean and typically involved two sides fighting each other for valuables such as Hydrolator Crystals.