Commercial Diving 101

Commercial divers solve complex tasks, often in deep waters. But what exactly do they do?

Divers come in many shapes and sizes. Strictly speaking, we can divide them into four types: recreational, technical, professional and commercial divers. Recreational divers make up the majority of the group. Training allows recreational divers to descend up to 130 feet with scuba gear.

Technical divers can go beyond 130 feet, and will utilize gear such as rebreathers. Professional divers are divemasters, dive guides, dive instructors and course directors. These people guide or train the other two groups. All three groups belong to an organization such as PADI, SSI or NAUI. But what about commercial diving?

Commercial Diving Basics

Commercial divers are in a completely different category. They dive not to train recreational divers, but to complete job-related tasks. Commercial diving require specific job training in addition to dive training. Dedicated commercial-diving schools usually conduct the necessary training. National boards for commercial diving oversee these schools. But what kind of work does a commercial diver do? Four of the most typical commercial diving careers follow.


Construction divers work in harbors, on bridges, or in other situations where they must maintain or build large-scale construction in water. They also do underwater surveys, work on coastal protection, and work on laying, inspecting and maintaining underwater cables and pipelines. Diving in these conditions requires commercial-dive training using both types of scuba units and surface-supported equipment. Divers must also learn about a range of tools and techniques, such as welding. Divers can descend up to 200 meters/600 feet, which requires extended decompression times. Saturation diving, wherein divers spend great times at depth, is often used, as once their tissues have become fully saturated with nitrogen, their decompression time does not increase (unless they move to a greater depth). After their shift is done (and these can last 12 hours or more), divers return to the surface and decompress in a chamber.


Offshore divers are usually associated with gas or oil platforms, and may work on the construction and maintenance of rigs, as well as the actual drilling process, where they may inspect the drill and make any repairs needed. They can also perform visual inspections of underwater equipment. Divers usually complete these types of dives with surface-supported equipment. Saturation dives may apply for deeper projects. Offshore commercial diving can be one of the most dangerous jobs in the world.


HAZMAT is shorthand for HAZardous MATerials, and HAZMAT diving takes place where there is significant risk of exposure to pollutants that are hazardous to human health, which can be anything from raw sewage to radiation-contaminated waters. Tasks can include repairs to filters, valves, or other mechanical equipment, to surveying and sampling contaminated water. This form of diving, in addition to commercial-diving training, requires HAZMAT training and specialized equipment, including a HAZMAT drysuit, as many chemical pollutants can penetrate the material of traditional drysuits.


Commercial divers also find their trade in salvaging. Salvage divers sometimes work independently, searching for wrecks, flotsam or jetsam, which they subsequently claim, salvage, and try to sell for a profit. Other salvage divers work as subcontractors to commercial shipping companies or governments, salvaging goods lost or, as in the case of the Costa Concordia cruise ship which ran aground in Italy, to salvage and remove a wreck that is deemed to pose a threat to the environment or a problem for ship routes.

There are many other jobs that commercial divers might undertake, in particular within rescue services, the police and the armed forces, but the above are the main fields within the private sector. Ever thought about becoming a commercial diver? Share your story!