Flat Preloader Icon

Underwater Welding: What You Need to Know


Underwater welding is a skill set, not a job title. Welders who actually perform this are called “commercial divers.” These professionals perform a highly technical skilled job to inspect, maintain, and repair pipelines, offshore oil drilling rigs, dams, ships, locks, nuclear power facilities, sub-sea habitats, and more. It is because of underwater welders that we have bridges to cross a river, receive power from a hydroelectric plant, or fill a glass with tap water every day. 

Being a commercial diver requires a number of diverse skill set which includes hyperbaric chamber operation, dynamic problem solving, and even first-aid and safety training. This is why it’s one of the most lucrative fields and one of the most well-paid occupations. Here we answer some questions you might have on your mind about underwater welding. 

Underwater Welding: How it works 

Hyperbaric welding or underwater welding has been there since the 1930s. There are inland hyperbaric welders that work on dams, seacraft, and bridges and there are offshore welders who work on oil rigs, ships, pipelines, and underwater habitats.

This welding process is just like welding on land in that both use the same basic equipment and even apply the same techniques. This is why one must be a professional welder before even becoming a commercial diver. 

Welding underwater is no joke and requires a lot of safety measures. Electricity and water really don’t make a good combination and it definitely spells trouble. But how does it work exactly? The answer is through processes called Dry Welding and Wet welding. 

Dry Welding

For Dry welding, a dry chamber system is used. A temporary hyperbaric chamber, which is the work area, is used to block or prevent the water from spilling in. The chamber can fit three welders at a time. A seal is created around the structure that needs to be welded and the water gets flushed out through a connected hose and then replaces it with certain gases like helium and oxygen. 

A ground crew controls fans that allow the exchange of exhausted air with fresh air. Shielded Metal Arc Welding (SMAW)  or Stick Welding and Flux-cored Arc Welding are mostly used during dry welding but Gas Tungsten Arc welding (GTAW), Gas Metal Arc welding (GMAW), and Plasma Arc welding (PAW) can also be used.   

underwater welding
Official U.S. Navy Page from United States of America (Wikimedia Commons)

Wet Welding

Some, although rarely, also use wet welding which is more of a last resort option. Aside from the fact that welders do not have anything to protect them from the water, there’s that high chance of a weld to cool down too quickly causing it to crack. For this option, Shielded Metal Arc Welding or Stick Welding is the most effective. 

With this method, underwater welders produce an electric art in the middle of their electrode and metal that needs to be welded. They start by putting their electrode on the targeted surface and signal their team to flip the current that generates 300-400 amps of electricity through direct current (DC). You might be asking how is it that they don’t get electrocuted?

The key to this is the thick layer of gaseous bubbles that are produced by the electrodes’ flux or external coating that covers the weld and then shields the electricity from water and other corrosive gasses and oxidizing compounds. For wet welding, other welding processes like Flux-cored arc welding (FCAW) and Friction Welding (FW). 

Is underwater welding dangerous?

Yes. That’s pretty straightforward but to be honest, underwater welding is dangerous and it involves a lot of risks. First on the list is the risk of being electrocuted since saltwater is a very good conductor of electricity. That’s why we were always taught as kids to avoid wet surfaces whenever we hold anything that has a source of electric power like a hairdryer.

Other risks include drowning which is usually caused by water pressure, explosions caused by the mix of hydrogen and oxygen gases, decompression sickness which is a common concern for commercial divers due to the build-up of nitrogen bubbles in the bloodstream, and hypothermia because of working in dark and cold conditions for many hours. 

For this reason, underwater divers need to undergo rigorous training before they can start their careers as commercial divers. This brings us to underwater welder’s salary and requirements. 

Underwater Welding salary and requirements

Underwater Welding Requirements

For you to become an underwater welder, you should:

  • Have the ability to swim
  • Commercial Diving Certification
  • AWS Certified Welding Training
  • Mechanical Aptitude
  • High School Diploma or GED

Underwater Welding Salary

Underwater welding can be risky as we have already established, and because of that, it now becomes a highly paid occupation. According to the U.S. Bureau of Labor Statistics, an underwater welder’s mean annual salary is $59,470 a year with a mean hourly rate of $28.59. That comes with salary increases in a short amount of time depending on your skills. Just so you know, top welders earn up to $150,000 per annum. The opportunities for welders are endless that’s why a career in welding will always be rewarding.