Should deep stops ever be used by recreational divers? There are plenty of arguments both for and against this practice, though the harshest critics point out that deep stops should be used only by professional scuba divers. A deep stop is basically an additional stop that is made during ascent, and those in favor of them believe that deep stops can serve as an additional barrier to decompression sickness. Let’s take a closer look at the argument about whether deep stops are appropriate for recreational divers.
Understanding the Deep Stop
A deep stop is more than just a simple variation of a regular decompression stop, as a decompression stop is a simply a stop a diver takes to spend time in shallow water before surfacing, in order to allow for the elimination of excess nitrogen from the bloodstream. Decompression stops help to prevent decompression sickness, which is caused when bubbles form in the bloodstream and tissues.
There has been much research in support of decompression stops, so much so that they are increasingly becoming part of standard safe diving procedures; while divers who were certified long ago may not have used decompression stops often, new divers are taught using the latest science. In recreational divers, decompression stops are known to drastically reduce the chances of neurological decompression sickness.
In spite of all precautions and following ascend tables and computers, it was discovered that many divers still faced decompression sickness on rapid ascent. This was compounded by the fact that there are many different ascent tables available, and each is backed by scientific evidence. Over the years, various experts have prescribed a slow ascent – as slow as three feet per minute – while others have advocated a rapid vertical ascent – as fast as one foot per second. There is still no international consensus on a table of appropriate ascent rates.
Due to these difficulties, J. S. Haldane, a scientist who studied fish and who often had to make deep stops to deflate his specimens’ swim bladders, proposed the ‘deep stop’ after noticing that he felt much less fatigued after dives during which he made the types of stops which are now known as deep stops. His theory was that a strategic stop taken at a depth where the pressure was exactly half of what it would be at a diver’s deepest descent point would substantially reduce the chances of decompression sickness. At the time, there was much opposition to the concept and there have been many naysayers ever since. Sir Leonard Hill, a physician from Britain, went as far as saying that decompression should occur by sheer vertical ascent to the surface; while we know today that this is not true, it is interesting to consider how thinking about decompression has changed over the last several decades.
Haldane prevailed in convincingly arguing his viewpoint, and fellow ichthyologist Richard Pyle was a strong and early advocate of the deep stop, as he made some of the same observations as Haldane did; in fact, the deep stop is often referred to as the Pyle Stop.
Relevance in recreational diving
The depth and length of recreational dives varies, as does the physical condition of recreational divers. While some of us are in fantastic shape, many of us earn our scuba diving money at sedentary jobs and many of us are not in the best physical condition, putting us in a higher risk category for nitrogen and inert gas poisoning.
Decompression sickness, which is also known as DCS, is a dangerous medical condition that occurs when bubbles form in the bloodstream and tissues following a rapid decrease in pressure as a diver ascends to the surface. While many cases of DCS are not life-threatening, even a mild case can be terribly painful and can completely ruin a vacation. Making appropriate decompression stops can help to eliminate the potential for decompression sickness, but advocates of deep stops point out that divers who make deep stops may be protecting themselves even further.
Why You May Decide to Use Deep Stops
Professional divers often descend to substantial depths and risk inert gas accumulation. The deep stop makes sense for such divers, but does it make sense for recreational divers? The tolerance of bodies to decompression sickness varies across gender, age and fitness level. Therefore, the ascent profile that best suits a U. S. Navy Seal or a professional deep sea diver may not necessarily suit recreational divers the same way.
Consider a 100 feet (25 meters) deep dive; this is a fairly normal depth for many recreational divers. Most experts recommend a decompression stop of five minutes once a depth of 20 feet has been reached on ascent. The total time to surface from the depths is still less than 10 minutes, and it may not be enough time for the body to rid itself of the gases that have accumulated. If you consider a deep stop taken at half the depth (50 feet) for another five minutes, then the total time of ascend increases dramatically, giving the body even more time to expel unwanted gases.
Criticisms of Using Deep Stops in Recreational Diving
Those who are skeptical of deep stops for recreational divers complain that there isn’t enough evidence based research that successfully demonstrates the positive effects of deep stops, and to be absolutely fair, the jury is still out as far as science is concerned. Numerous scuba diving magazines and discussions forums are peppered with heated discussion on the merits of using the deep stop, but it’s important to note that skeptics do not have any negative research available to disprove the efficacy of using deep stops in recreational diving. Many first-hand testimonials vouch for the use deep stops. Even free diving pearl hunters, who often face the risk of rapid descent and decompression sickness, use a technique similar to deep stops to reduce the effects gases have on their bodies.
Ultimately, the decision concerning whether to make deep stops or not is yours to make. You know your body better than anyone else does, and it may respond well to deep stops. Discuss the pros and cons with an expert you trust and weigh the pros and cons to determine whether to give this method a try.