Commercial Versus SCUBA: Diving Essentials

Commercial Versus SCUBA: Diving Essentials

Imagine a commercial diver. What pops into your head?

Serene underwater environment. Colorful fish. Sun shining from the surface of peaceful water, mixed with the whirl of bubbles from the diver’s exhale.

Oh – and everything’s in slow motion.

Reality looks different – this visual might work well for SCUBA, but not commercial diving.

scuba diving certification

Diving Work Environments & Responsibilities

Let’s put the microscope on commercial first:

Commercial divers often work in hostile, challenging environments.

They swim in extreme depths, low to zero visibility waters and communicate constantly with a surface team. Their work is often mechanical in nature, as almost everything deals with the construction and energy industries.

They work on structures partially or fully submerged in the water.

Commercial divers work in two primary geographical locations which determines much of their work. Here’s a few examples:

SCUBA diving comes in two flavors: Recreational and professional.

The majority of SCUBA divers practice scuba in a recreational capacity, ranging in experience from novice to veteran. They are the explorers of the sea.

Mike Hemion, Divers Institute of Technology Instructor expands on opportunities in recreational diving.


DIT Instructor Mike Hemion

“SCUBA” can be used for a wide variety of recreational hobbies such as marine life sightseeing, underwater hunting and foraging, and  traveling to exotic underwater locations throughout the world. Underwater archaeology, and wreck diving are also common uses for SCUBA.”

The professional world opens SCUBA divers to many different fields:

  • Instructor
  • Media
  • Scientific
  • Commercial

Wait, commercial?

Yes, occasionally commercial diving also uses SCUBA, but only for a few types of jobs, as Bradley Peterson, Divers Institute of Technology instructor, explains.

“SCUBA has a small niche. Jobs that need the diver to stay off the project for example: Unexploded Ordnance (UXO), Noxious / Invasive weed removal, forensic work, most small ship husbandry cleaning inspection type stuff.”

Location also separates SCUBA divers:

“Typically SCUBA is not used offshore. Never say never but…yes never,” Bradley says.

Open or Closed: SCUBA & Commercial Equipment

Professional divers must have a proper understanding of their gear. It ensures the safety of the diver and efficiency for all projects they undertake.

The primary difference between scuba and commercial divers’ gear is in the air supply.

A SCUBA diver always uses a tank, or (self-contained underwater breathing apparatus).

The majority of SCUBA systems are open-circuit in nature, complete with an air controlling device called a regulator. Others recycle the gases in a re-breather (close-circuit system). These may also use regulators or injectors to control the gas flow.


DIT Instructor Brad Peterson’s regulator

Because SCUBA systems are completely self-contained, the diver has complete freedom of movement and can swim with great mobility. The drawback, however, is their limited air supply. With no way to replenish their air, divers are forced back up to the surface.

On the flip side, commercial divers primarily utilize a surface-supplied diving system (SSA). SSA consists of lengthy, colored hoses (umbilicals) connecting from a gas supply source on the surface to the diver’s helmet. Communication is hardwired in as well.


DIT Student completing a surface supplied dive.

The umbilical provides continuous airflow so the diver can stay in the water for a longer period of time. Commercial divers must always be aware of their umbilicals’ position, though, as entanglement poses risk.


DIT Student Diver with bail-out bottle sitting standby.

Even with umbilicals, however, commercial divers wear an air reserve tank (bail-out cylinder) for emergency situations. This makes the SSA system somewhat confusing to a new student, as Bradley points out.

“Generally they [students] have no idea which is which. If they are already SCUBA, they know there is a difference but no clue how much until they dive the hats for the first time.”

If time is of the essence in a search and rescue operation, commercial divers will choose a single scuba over SSA.

DIT’s SCUBA course

During month six of DIT’s program, students will participate in scuba and non-destructive testing (NDT) training.


DIT Class SCUBA diving at Alki Beach

This course is reserved for later on in the program intentionally.

“Before doing SCUBA, the students will have had more time in the water on campus in more controlled environments before they experience dive sites around Seattle that have deeper water, stronger currents and varied conditions,” Mike says.

He also notes that the course allows students to experience the full spectrum of water sites and facilities.

“First we start with a public Seattle pool; then we move on to the salt water locations in the  Puget Sound including Alki Beach, Shilshole, and Bell Harbor to name a few, and freshwater lakes and rivers throughout the area all depending on conditions.”


DIT Class SCUBA diving on the Skykomish River

In the first part of the course, students train more with NDT. This complements the overall course well, since it allows them to work with their hands among maritime materials such as ships and pilings.

“Because off campus SCUBA dive sites can contain real world materials like boat hulls, pilings, and steel seawalls for inspections and surveying that can pair nicely with the NDT portion of the course,” Mike says.

Watermanship: Invaluable SCUBA Skillset

In the end, commercial divers still apply their “SCUBA skills” even if they’re not using scuba equipment on the job.

“Watermanship is a skill perfected in scuba and helps make surface supplied diving more comfortable and controlled by the diver. Your buoyancy adjustment is completely different in SCUBA. Because of this, divers trained in SCUBA can have better body coordination during mid-water work and projects,” Mike says.

Written for Divers Institute of Technology by Matt Smith, Creator of Water Welders.

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