Purpose. This chapter discusses the planning associated with mixed-gas diving
operations. Most of the provisions in Chapter 6, Operations Planning, also apply to
mixed-gas operations and should be reviewed for planning. In planning any
mixed-gas operation, the principles and techniques presented in this chapter shall
be followed.
Scope. This chapter outlines a comprehensive planning process that may be used
in whole or in part to effectively plan and execute diving operations in support of
military operations.
Additional Sources of Information. This chapter is not the only source of information
available to the diving team when planning mixed-gas diving operations.
Operation and maintenance manuals for the diving equipment, intelligence
reports, and oceanographic studies all contain valuable planning information. The
nature of the operation will dictate the procedures to be employed and the planning
and preparations required for each. While it is unlikely that even the best
planned operation can ever anticipate all possible contingencies, attention to detail
in planning will minimize complications that could threaten the success of a
mission.
Complexity of Mixed-Gas Diving. Mixed-gas diving operations are complex,
requiring constant support and close coordination among all personnel. Due to
extended decompression obligations, mixed-gas diving can be hazardous if not
properly planned and executed. Seemingly minor problems can quickly escalate
into emergency situations, leaving limited time to research dive protocols or operational
orders to resolve the situation. Each member of the diving team must be
qualified on his watch station and be thoroughly competent in executing applicable
operating and emergency procedures. Safety is important in any diving
operation and must become an integral part of all operations planning.
Medical Considerations. The Diving Officer, Master Diver, and Diving Supervisor
must plan the operation to safeguard the physical and mental well-being of
each diver. All members of the team must thoroughly understand the medical
aspects of mixed-gas, oxygen, and saturation diving. A valuable source of guidance
in operations planning is the Diving Medical Officer (DMO), a physician
trained specifically in diving medicine and physiology.
Mixed-gas diving entails additional risks and procedural requirements for the
diver and the support team. At the surface, breathing a medium other than air
causes physiological changes in the body. When a diver breathes an unusual
medium under increased pressure, additional alterations in the functioning of the
mind and body may occur. Each diver must be aware of the changes that can occur and how they may affect his performance and safety. Mixed-gas diving procedures
that minimize the effects of these changes are described in this and the following
chapters. Every mixed-gas diver must be thoroughly familiar with these
procedures.
Typical medical problems in mixed-gas and oxygen diving include decompression
sickness, oxygen toxicity, thermal stress, and carbon dioxide retention. Deep saturation
diving presents additional concerns, including high pressure nervous
syndrome (HPNS), dyspnea, compression arthralgia, skin infections, and performance
decrements. These factors directly affect the safety of the diver and the
outcome of the mission and must be addressed during the planning stages of an
operation. Specific information concerning medical problems particular to various
mixed-gas diving modes are contained in Volume 5.
