The earliest "diving gear" involving turtles was not a full helmet, but rather protective eyewear.
: They thinly sliced and polished the outer layer of the shell until it was transparent, allowing them to see clearly while diving for pearls. Turtle Shells To Diving Diving Helmets
: In 1837, Augustus Siebe developed the "standard diving dress," featuring a brass and copper helmet that allowed air to be pumped from the surface. The earliest "diving gear" involving turtles was not
During World War II, a specific type of headgear earned the "turtle" moniker due to its shape: British Mk III Helmet Go to product viewer dialog for this item. Turtle Shells To Diving Diving Helmets
: Persian divers used polished tortoiseshell to create diving goggles.