The arena of public safety diving is as vast and challenging as the dive operations that teams perform. Dive units across the nation do not operate under one national recognized standard or set of rules. And as such, they face unique obstacles specific to themselves and their jurisdiction. But even with a lack of standardization, all divers can perform demanding and challenging operations safely, thanks to new technological breakthroughs in equipment design and development.
The National Incident Management System, or NIMS, classifies a public safety dive team as a law enforcement unit equipped and trained to perform a variety of location and recovery operations, as well as provide safety divers for special events. With this in mind, scientists, designers and manufacturers needed to create equipment that allows for safety, comfort and versatility. In addition, equipment had to be developed that would protect the diver from contact with pollutants and contaminants, and is also cost effective for teams operating on limited budgets.
What lies below
Most public safety dive teams are chartered to perform all or some of the three specific types of diving operations: Body recovery, vehicle recovery and evidence recovery. Each of these presents specific contaminant concerns as well as challenges not found in sport diving. Vehicles in the water often leak gasoline, battery acid, brake fluid, transmission fluids and oils which can easily burn divers' skin or create other complications if absorbed into the skin or ingested via a regulator that dangles from the mouth.
Body recoveries are probably the most challenging concern for public safety units for several reasons. Bodies begin to deteriorate at a high rate after life is extinguished. The decaying victim leaches bodily fluids, including urine, feces, gastric juices, cerebra-spinal fluid and others into the surrounding water. In addition, the high concentration of contaminants provides a breeding ground for bacteria and viruses to grow and infest.
Diving manufacturers began analyzing the needs of public safety teams and looked at ways to mitigate exposure to such contaminants. Advances in exposure systems, respiratory and air delivery units, and even the ability to add underwater communications were developed. Thus the standard dress for public safety divers was born.
Wetsuits, by their name, are designed to trap a thin layer of water between the suit fabric and the skin. The body temperature of the diver heats the water, which in turn keeps the diver warm.
However, due to the contaminants present in most public safety dives, wetsuits quickly became taboo. The wetsuit's design issues in contaminants and traps them next to the diver's skin, thus allowing some contaminants to be absorbed into the body.
Dive equipment manufacturers and agencies sought to correct this design flaw by introducing a newer and safer exposure suit, which is referred to as a dry suit. Dry suits are designed to completely encapsulate the diver and prevent water from entering by using special latex seals around the wrist and neck. In addition, the attached dry gloves and dry hoods kept water away from the majority of the body, with the exception of the face.
Dry suits were initially made from neoprene rubber. However, neoprene, while keeping water out, would still absorb contaminants on the external fabric layer. A diver could be exposed simply by removing the suit after a particularly nasty dive. Alternative suit materials and designs were invented to minimize this risk and also to make the suit more comfortable. Dry suits made from bi-laminate, tri-laminate and polyurethane were developed, but each had its limitations when operating in certain contaminants like gas and oil.