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What if a diver surfaces from a dive and fails to complete required decompression stops? If so, preventative action (or harm minimisation) can reduce the likelihood of decompression sickness (DCS).
The guidelines in this segment outline industry standards for decompression stop diving and what can happen after omitted decompression.
It's important to highlight the key difference between a safety stop and having to decompress when diving.
To add extra conservatism to a no stop dive, making scuba safety stops allows for the controlled off-gassing of nitrogen before surfacing.
Despite not being a compulsory procedure, performing a three minute safety stop at 5 metres is "highly recommended".
In other words, skipping a safety stop is acceptable if ascending to the surface, or exiting the water, is the overriding factor.
However, all reputable scuba training agencies (especially for technical and trimix diving) consider decompression stops as mandatory procedures, so that divers surface with a "reduced" risk of developing decompression illness (DCI).
Pro Tip: Most scuba divers will have a reasonable chance of avoiding decompression injuries even when missing a recommended safety stop. But, surfacing before any (or all) mandatory decompression stops are complete, means the likelihood of getting bent (decompression sickness) is significantly greater.
Scuba divers plan and track decompression following a decompression model. It assists the release of excess inert gases, usually nitrogen, dissolved in their body tissues.
The decompression model, based around US Navy dive tables, accounts for several variables after supersaturation, including:
In scuba diving, decompression can be a continuous procedure, or a staged process. Hence, the interruption of the ascent occurs at predetermined depth intervals (e.g. deep stops).
Even so, the entire ascent is part of the strategy used when a diver decompresses. Thus, an ascent rate that is too fast can be critical.
Omitting, or delaying, decompression theory exposes scuba divers to a greater risk of symptomatic decompression sickness. In severe cases it may also cause serious injury or death.
Any diver with an omitted, interrupted, or delayed decompression stop should adopt the following safety protocols and procedures:
Pro Tip: Another guide explains why the contentious technique of in-water recompression (recompressing a scuba diver underwater) actually takes place in certain areas of the world.