The human eye is unable to focus when in direct contact with water, and an air space must be provided.

[19] Tools and equipment too large or too heavy to be carried by a diver are generally lowered to the worksite from the surface platform.

Life support equipment must be maintained and tested before use to ensure that it remains in serviceable condition and is fit for use at the time.

Inadequate pre-dive checks of breathing apparatus can have fatal consequences for some equipment, such as rebreathers, or may require the diving operation to be aborted without achieving its objective.

Some highly effective methods for disinfection can damage the equipment, or cause accelerated degradation of components due to incompatibility with materials.

The commercial diving market is relatively small, but occupational safety issues keep cost of operations high and there is work that must be done in support of various industries, particularly the oil and gas industry, that make money available for high reliability equipment in small quantities.

Technical diving is a niche market, where the buyers are willing to take higher risks than commercial operators, and there is enough money available to support a small number of manufacturers developing new technology.

Scientific diving is also a small market, and tends to overlap the other sectors, using what is available, and occasionally driving development of new technology for special applications.

It is a non-profit, global organization with more than 1,300 members, which promotes scuba diving through consumer awareness programs and media campaigns such as the national Be a Diver campaign; diver retention initiatives such as DiveCaching; and an annual trade-only event for businesses in the scuba diving, action watersports and adventure/dive-travel industries, DEMA Show.