A tiny submersible vessel, developed along with the Griffon project, the SGS become a vital tool to the G-Graspers. With hull and wire coverings that were reinforced with radiation proof metals and materials, the mini-sub was a perfect surveillance craft for use on Godzilla. One of the SGS' first missions was to be sent to follow the tag that was attached to the swimming behemoth. Traveling only a few mere feet away from the living mountain of flesh, the SGS relayed important information of where Godzilla was heading.