There are many life-threatening dangers associated with underwater welding, because of the combined risks of welding and being under water with pressure. Not a lot of people can handle a job where explosions can happen, sharks can attack and water pressure can cause long-lasting effects. However, jobs like these generally offer great pay to offset the danger.
There are two types of underwater welding, "wet" and "dry" welding. Dry welding is when a hyperbaric chamber is placed around the item to be welded, and the chamber pumps the water out of it, much like a submarine does. Wet welding is using electrodes from special welding equipment to connect with electrodes in the water and metal.
Sharks and large ocean predators are always a potential threat when welding underwater, as well as the diving suit becoming damaged or the oxygen tanks becoming loose or emptied. The ocean current can actually carry a welder off, which can result in disastrous consequences. Nitrogen can build up in the diver's blood and create deposits. Wet underwater welding adds the danger of being shocked, or producing a mixture of oxygen and hydrogen together in bubbles in the arc, which can lead to an explosion. If a diver surfaces too fast, he is always in danger of getting the bends (severe pain in joints that is cause by not properly depressurizing). Of course, there is the most common death involved with water - drowning.
Dry underwater welding sounds much less dangerous; however, companies that hire underwater welders generally pay very well for completing dangerous underwater jobs such as this.