When you ascend above the ceiling by more than 0.6 m (2 ft), the ceiling parameter turns red, a red arrow pointing down appears, and an audio alarm is generated.
In such event, you should descend below the ceiling level to continue the decompression. If you fail to do so within three (3) minutes, Suunto D5 locks the algorithm calculation and displays Locked instead, as shown below. Note that the ceiling value is no longer present.
Suunto Fused™ RGBM 2 algorithm is locked for 48 hours if you omit to take decompression stops for longer than three (3) minutes. When the algorithm is locked, no algorithm information is available and Locked is shown instead. Locking the algorithm is a safety feature, highlighting that the algorithm information is no longer valid.
Algorithm locked in Timer view:
Algorithm locked in No Deco view:
In this state, you significantly increase your risk of decompression sickness (DCS). Decompression information is not available for the next 48 hours after surfacing.
It is possible to dive with the device when the algorithm is locked, but instead of the decompression information, Locked is shown. Diving while the algorithm is locked resets the algorithm lock time back to 48 hours when you surface.