Antique helmet.

sketchfab

The antique diving helmet appears to be an outdated relic. This peculiar diver's helmet was likely a source of distress, had it actually existed. It doesn't seem to have been designed for attachment to a rubber suit, so we can infer that it simply rested on the shoulders. If the diver stumbled or lost his footing, the helmet would rapidly fill with water. The model is prepared to give your characters a distinctive retro look.