Classical Haldane-type decompression calculation assumes that all gas is dissolved into the tissues, and remains dissolved as long as the maximum tissue tensions are not exceeded. Bubbles are assumed to form only when the ascent rate or the m-values are exceeded. As the pressure gradient is invertedly proportional to the surrounding pressure, the diver is brought as shallow as possible, as fast as possible, in order to maximize offgasing.
Doppler-studies show, that microbubbles are present on all doves. Therefore the effects of free gas need also to be considered in decompression calculations
The Suunto RGBM was designed to protect the recreational diver from the effects of micro-bubble build up. It incorporates a bubble-factor based tracking system to adapt the decompression requirement based on conduct dive profiles. The maximum ascent provides maximum offgassing and a clean decompression curve. A 3min recommended safety stop is added to deal with adverse ascent rate violation. An extended surface interval is promoted when microbubbling is present.
The Suunto Deep Stop RGBM algorithm increases microbubble suppression on deep dives even further by introducing iterative deep stops.
The first deep stop is placed at half the pressure difference between your maximum depth and the ceiling depth. Once the deep stop depth is attained, the next deep stop will again be introduced half-way to the ceiling, and so on. Once the ceiling depth is reached, continous decompression is employed for staging the end of the profile.
In the Suunto D9 and Suunto Vytec DS the user can choose between the familiar Safety Stop providing Suunto RGBM, or the new Deep Stop RGBM.