A loose-fitting Mechanist helmet designed for undersea exploration, useless and worthless, serving only as a distraction tool. Can be found only on Markham's Isle along with other maritime miscellany, such as the Anchor, Sextant, Navigator's Compass and Chart Compass, and Mechanist devices, such as the Drilling Machine.
The Mechanist Frogman can be seen wearing this helmet which renders him unable to be knocked out by either Blackjack or gas attacks and also protects him from being drowned.