Underwater Welding & Burning: 6,500 – 10,000° F Under the Sea

Underwater Welding & Burning: 6,500 – 10,000° F Under the Sea


Under the water, metal sounds different. It’s high pitched – but muffled – like a siren entering a tunnel. It dissipates quickly out into the waves.


Photo Credit Sonny Schreiner

Commercial divers know the sound well.

Of all the ways that commercial divers work with metal, underwater welding remains one of the hottest topics. It’s talked about on internet forums, given high marks for salaries and slapped onto “dangerous jobs” lists.

Underwater welding isn’t a career within itself. Many unknowingly substitute the word, “underwater welder” when referring to a commercial diver. On average, commercial divers perform very little underwater welding in comparison to other tasks.

Here’s a few examples of commercial diving jobs:

  • Salvage
  • Inspection
  • Underwater burning
  • Cleaning submerged materials
  • Underwater installations

In any case, underwater welding is still an important skill for commercial divers to obtain. It increases their arsenal of diving skills and allows for more employment opportunities.

Habitat or H2O: Underwater Welding’s Forms

When underwater welding is mentioned, what comes to mind? Probably this:

What you’re seeing here is a process called “wet welding.” In fact, underwater welding has a brother that no one talks about – dry welding (also known as hyperbaric welding).

Dry Welding

Dry welding also takes place underwater, but it incorporates a small habitat to insulate weld site from the surrounding environment. This process simulates a surface weld and, in general, provides a greater weld strength than wet welding.

Some dry welding habitats are built for two divers to tag team a project for a period of time. These hyperbaric chambers are used for major projects, such as sealing a large oil pipeline connected to an offshore oil rig.

Underwater welders also use smaller habitats. Mechanical engineers have even designed some to fit directly over the weld site, just large enough to encompass the diver’s hand and welding equipment.

Wet Welding

Using electricity directly in the water? Sounds terribly unsafe.

But wet welders are always properly prepared, using rubber gloves and darkening glass on their diving hats.

Unlike dry welding, which can incorporate many types of welding processes, wet welders use only SMAW or “stick welding.” Their sticks (electrodes) are waterproof. When welder-divers begin welding, the electrode emits a small gaseous shield around the weld site, temporarily keeping out water and corrosive gases like oxygen.

Wet welding also uses a special cable system that hooks up to welding equipment. Those cables contain a unique device called a knife switch. Think of it like the breaker box where you live.

It remains off until the diver is ready to weld.

Training & Prep for Metal Fusing

Facilities across America and worldwide provide courses for underwater welding. These are set according to the welding standards of national organizations like the American Welding Society and the British Standards Institution.

The Divers Institute of Technology offers a 3-week underwater welding and burning course  during their 7 month commercial diver program that takes students’ skill sets to the next level.

The first week begins primarily in the classroom where they learn about welding safety and technique. By the second week, student divers practice T-joint surface and wet welds in various welding positions.

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“Half the students think that topside welding is hard, and that underwater welding is easy, and the other half thinks it’s the other way, that underwater is hard and topside is easy. It’s always like that,” Josh Oxley, DIT underwater welding and burning instructor, said.

Previous welding experience from students is welcome, but not required. Without a welding background, students still learn basic welding techniques and put their skills to the test.

In the final week, instructors focus on underwater burning, where students slice and dice in the nearby Lake Union.

The first time they try to burn underwater and achieve a goal that we set for them, they usually come up grinning,” Josh said.

Career Application

Unfortunately, there’s no universal welding or underwater welding certifications. Employers often issue their own “certification” for each specific welding project.

110624-N-XD935-040 VALPARAISO, Chile (June 24, 2011) Navy Diver 2nd Class Ryan Arnold, assigned to Mobile Diving and Salvage Unit (MDSU) 2, welds a patch onto an underwater structure during a subject matter exchange with Chilean divers. MDSU-2 is participating in Navy Diver-Southern Partnership Station, a multinational partnership engagement designed to increase interoperability and partner nation capacity through diving operations. (U.S. Navy photo by Mass Communication Specialist 1st Class Jayme Pastoric/Released)

(U.S. Navy photo by Mass Communication Specialist 1st Class Jayme Pastoric/Released)

After graduating from dive school, you can deepen your knowledge of underwater welding by applying for gigs that involve wet or dry welding processes. Even if you’re not directly involved, you can assist and observe other underwater welders.

Underwater welding is an exciting field with many possibilities. Be part of the elite few who strike an arc under the waves!

– Written for DIT by Matt Smith, Creator of Water Welders.

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