When Are Dive Decompression Stops Necessary?

Scuba diving is a fun, exciting recreational activity. The prospect of exploring the depths of quarries, lakes, rivers and oceans is alluring. Scuba diving, however, requires training in order to prepare to participate in the activity safely. Decompression stops are an important and necessary part of safe diving at any depth, and knowing when to do them is essential knowledge.

  1. Definition

    • A decompression stop, also known as staged decompression or a deco stop, is an action carried out by a scuba diver in which she spends a set period of time at a certain depth of shallow water. A diver performs a decompression stop at the end of a dive, before reaching the surface of the water. It may require more than one stage.

    Effect

    • Divers use decompression to clear their body of certain gases that have been absorbed while they were underwater. The decompression stop helps avoid decompression sickness, also known as the bends, that occurs when dissolved gasses form into bubbles inside the body and which can be very painful and potentially lethal. During a decompression stop, inert gasses in the body that have been collecting throughout the dive are dissolved as pressure is relieved.

    Depth and Length

    • Over the years, the recommended depth for decompression stops has varied from 10 feet to 15 or 20 feet. Today, the standard recommendation is a stop of 3 to 5 minutes at 20 feet. According to Brian Morris of Divers Support, the depth recommendation is based on evidence that deeper stops were better for eliminating nitrogen gas. This guideline, however, will vary depending on the type of diving you do. A stop of 3 to 5 minutes at 15 feet may be fine for a sport diver but inappropriate for a technical diver, who will need longer and more frequent stops, depending on the length and depth of his dive.

    Making a Rule

    • Decompression stops are an important part of scuba diving, and they can save your life. Many instructors recommend making multiple stops at different depths. Morris recommends making a rule of thumb for yourself and then sticking to it. He suggests making your first stop for 1 to 2 minutes at a depth equal to half of the deepest depth of your dive. So, a dive of 50 feet would require a first stop at 25 feet. Then ascend 10 feet for another minute until you've reached 15 feet, at which point you should remain stopped for 2 to 5 minutes. He also notes that stops at 20 feet are always required, no matter what your dive profile is and what other stops you make during you ascent.