If you plan your dive and dive your plan, there really is no reason that you should have to perform an emergency decompression stop on a recreational dive. However, everyone makes mistakes, and sometimes it’s easy to get distracted and stay down too long or stray too deep. Sometimes, exceeding your planned maximum depth or dive time happens due to forces beyond your control — staying below to help a buddy or because of an emergency situation.
As a recreational diver, you should never plan to exceed (or even dive right up to the no-decompression limits), but if you accidentally find yourself past your dive time or maximum depth and running to deco, it’s good to know what to do.
Emergency Decompression Guidelines
- If a no-decompression limit is exceeded by 5 minutes or less: make an 8 minute stop at 15 feet and remain out of the water for 6 hours before diving again.
- If a no-decompression limit is exceed by more than 5 minutes: make at least a 15 minute stop at 15 feet and remain out of the water for a minimum of 24 hours before diving again.
Will You Remember These Numbers on a Dive?
The emergency decompression rules are easy to memorize, but in an emergency situation, it is quite likely that a diver’s memory may not be functioning at full capacity. It is a good idea to write this information down on a slate or even on the back of your computer so that you have access to it in the unlikely event of an emergency decompression situation.
How Will You Monitor Your Emergency Decompression Stop?
Consider the series of events that leads a diver to find himself requiring emergency decompression. While a diver may simply forget to check his computer or watch, another likely situation is that he needs to perform emergency decompression because of a computer or watch failure.
Without a timing device, he may have no way to monitor the length of his emergency decompression stop. Unless his buddy is nearby, the only option left is to count out the minutes. If a diver finds himself alone and without a timing device, he may have to simply wait at the stop depth until he has used most of his breathing gas (hopefully exceeding the minimum required stop time) before surfacing slowly. Divers should be prepared for this possibility
Most regulators have an analog depth gauge, but in an absolutely worst-case scenario, a diver relying only on a computer could find himself with no idea of his depth as well as his dive time. In this situation, an observant diver may be able to visually estimate his depth, but most divers would be hard pressed to hold themselves at exactly 15 feet with no depth gauge. At this point, the diver should make his best guess and estimate. Emergency decompression imperfectly done is still better than no emergency decompression at all.
Availability of Breathing Gas
Emergency decompression can only be performed as long as the diver has air left in his tank and/or has a buddy whom he can share gas with. This is yet another reason to always dive conservatively, and to plan to surface from a dive with plenty of gas in reserve.
There Is Nothing Inherently Wrong with Decompression
This entire article is devoted to emergency decompression stops and how to avoid having to make them, but keep in mind that there is nothing inherently wrong or mysterious about decompression, it’s just that recreational dive training doesn’t teach divers to plan for and safely make decompression stops. If you are interested in learning about decompression diving, just take a course. There are many excellent courses available for reputable technical dive training organizations including stage decompression diving.
The Take Home Message About Emergency Decompression
Divers would do best to avoid an emergency decompression situation altogether. Plan for an equipment failure by carrying a back-up timing device and an analog depth gauge, and by making a dive plan based on the recreational dive tables in case of a computer failure. However, even the best divers can make mistakes, and sometimes events simply conspire against you. By understanding the rules of emergency decompression, a diver is prepared for this possibility and can remain safe and confident in even the worst of situations.