Type 5 is the first mechanical sports watch to be perfectly readable underwater regardless of the viewing angle. As with all Ressence watches, the essence of Type 5 is its main function - the expression of Time. To achieve the best-ever readability underwater, the complete ROCS module - all 142 components - is immersed in 37.5 ml of oil.

It cancels out what is known as Total Internal Reflection. Type 5 has no crown - instead, the caseback is used both for winding and to set the time. However, to ensure maximum water-resistance, a new caseback has been specially developed for the Type 5. Dubbed the Ressence Compression Lock System (RCLS), it locks and compresses the gasket with two positions, ‘lock’ and ‘set’. An ingenious hydraulic shock absorber has also been specifically designed to prevent uncoupling of the magnetic transmission. Type 5's functions are a 90-second runner, minutes, hours, oil temperature and unidirectional bezel.