Deep-sea Rescue Equipment

The equipment used in deep-sea rescues is like something from a James Bond movie. From remote-controlled subs with robot arms to deep-sea diving suits, modern technology has greatly increased the odds of a successful rescue.

Remote-operated vehicles (ROVs) are a crucial part of deep-sea rescue. These underwater craft range in size from 2 feet long to the size of a small car. They're typically tethered to another submarine or surface ship. The power and remote capabilities are supplied by this tether, which also provides a conduit for the video and audio relay cables. ROVs are usually equipped with both video and still cameras. They also have remote-operated robotic arms with lifters, grabbers, pinchers and cutters. Many times an ROV is sent down to access the situation so the crew can decide the best course of action for response. If the disabled submarine is simply trapped or has lost power, the ROV can often cut it free or tow it to the surface.

Remote operated vehicle
Photo courtesy U.S. Navy
Remote Operated Vehicle Super Scorpio is retrieved after completing a pod delivery exercise during Sorbet Royal 2002.

Hard-shelled suits that can withstand pressure as deep as 2,000 feet, known as Atmospheric Diving Suits (ADS), were put into action in 2001. With a constant internal pressure of one atmosphere, the ADS allows divers to ascend to the surface at any rate of speed without requiring decompression. With this technology, human divers are now able to access situations firsthand, provide emergency life support and prepare the sub for mating, the process of joining the vessel to another.

Submarine Rescue Chambers (SRCs) are metal pods that can be attached, or mated, to a disabled submarine. These chambers remain pressurized and allow for the safe extraction of the crew. Once on board, the SRC detaches from the sub and ascends to the surface at a safe rate. There's a similar unit called a Transportable Recompression Chamber System (TRCS) that's used in the evacuation and recompression of deep-sea crew. A transfer lock attaches and forms an airtight seal between the sub's hatch and the TRC, allowing medical personnel to go back and forth in a pressurized environment. Like the SRC, the TRCS is pulled back to the surface by a cable and the crew is gradually recompressed.

Atmospheric dive suit
Photo courtesy U.S. Navy
The Atmospheric Dive Suit (ADS) is lowered into the water for a dive.

Another new addition to the deep-sea rescue fleet is the Emergency Evacuation Hyperbaric Stretcher (EEHS), portable, collapsible one-man chambers that are used to move individual sailors to safety in a pressurized environment. The EEHS was used in the extraction of the trapped miners in Somerset, Pa., in 2002. The air pressure that miners experience deep into the earth is similar to the water pressure that deep-sea divers endure. The EEHS provides safe transport to recompression chambers.

Baby's Got the Bends
 Decompression sickness, also known as "the bends," is a symptom that many SCUBA divers and submariners face when they ascend to the surface too rapidly. As you dive, pressure on your body increases, causing more nitrogen and oxygen to dissolve in your blood. Most of the oxygen is consumed by tissue, but not the nitrogen. The dissolved nitrogen is what causes the bends.

If you ascend too quickly, the nitrogen leaves your blood too fast and forms bubbles. These bubbles block tiny blood vessels. This can lead to strokes, heart attacks, ruptured blood vessels in the lungs and joint pain. Divers avoid the bends by following the recommended ascension rate. You can learn more about the bends in What if my scuba diving equipment failed?

In the next section, you can find out about deep-sea rescue training exercises.