|LEGO → System → Aquazone → Aquanauts|
1728 Crystal Crawler is a 1996 Aquanauts set. It includes 91 pieces. This version includes a plastic sea floor play stage. The set includes a yellow Aquanauts sub that has four propellers, two at the front and two at the back, two robotic arms, two wheels, one at the front and one at the back and a blue cockpit.