Diving - 1955 - Team wear

SOS Automatic Decompression Computer

One of the earliest dive computers was the SOS Automatic Decompression Computer; affectionately called the 'Bend-o-matic.' This computer was a fully mechanical analog device. It featured a balloon connected via a porous ceramic block to a sealed metal chamber, with a needle indicating the pressure inside the chamber. As the diver descended, the balloon was compressed, forcing gas through the porous ceramic block into the chamber. The deeper you went and the longer you stayed under pressure, the more gas was pushed through the ceramic. When ascending, the excess pressure in the sealed chamber attempted to equalize with the pressure in the balloon, causing the needle to return to a lower position.

One can consider it as a single tissue computer, unlike the eight or sixteen tissue electronic computers used today.