How does a super-compressor-watch work?
In normal diving watches, the case back sits very tight on the case. As the water pressure increases, the case back is pressed even tighter against the O-ring seal, which means that it wears out more quickly than with watches that are not used for diving. For this reason, modern diving watches should also be regularly checked for leaks.
In contrast to other watches, the case back of a super-compressor-watch is spring-loaded. Due to this wave-shaped spring, which is located on the edge of the case back, the case back base is already sealed before the O-ring seal is completely compressed. As the water pressure increases, the case back can move inward slightly, which increases the compression pressure on the O-ring and at the same time seals the watch even better. At lower compression levels, the O-ring is not fully loaded – this only happens at deeper depths when the water pressure becomes so strong that full compression is required and the spring presses completely on the O-ring.
Because the case back is not permanently pressed against the O-ring thanks to the spring when the water pressure is low, it does not wear out as quickly.