Dark Opel Scouts with High Commander Skull: Blue Visors are terrain scout who use the mini subs to travel around. Green Visors are the mark of the vehicle scouts who use jets to patrol the outer depths of the ocean. And finally the black visors on blue helmets are the boarding troops who attack other ships with high tech stealth equipment. They all wear black to blend in with the oceans dark environment. Commander Skull is a top notch General that is in charge of the fleet of Gems and takes great pride in it too. How he got his skeleton face nobody asks or wants to know and Skull is not telling anyway.