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Underwater Welding Equipment: Essential Accessories

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How many accessory tools do you carry to a dive job?

An experienced underwater welder could answer that question thousands of different ways, as every job is slightly different. Like topside construction, underwater welders can meet all kinds of unexpected challenges that require equipment ranging from a basic wrench to a full-fledged air-powered jackhammer.

But let’s think about the bigger picture. Regardless of the job type, all underwater welders require a core group of dive accessories, though they might not take all of them down at once. And purchasing this equipment can be a nightmare if you don’t know what characteristics you’re looking for.

From the moment you enter diving school (or even beforehand), you’ll be introduced to most of these accessories so that by the time you’re graduated, you’ll be old friends.

I base this core group on several characteristics:

  • Multi-use functionality
  • Light and portable
  • Increase productivity and efficiency

Here’s a “buyer’s guide” to this core group. Our first piece of equipment is somewhat of a “cover-all” for other tools, and I mean that in the literal sense.

Underwater Welding Core Accessories

1. Diving Gear Bag


An underwater welders will, in all likelihood, travel thousands of miles annually. And just as an intelligent businessman protects his documents with a briefcase, you’ll need a high quality gear bag for your equipment. A gear bag also serves as a one stop storage case where you can pack up and stay organized before and after jobs.

Price $30 – 150

Although $30 is a great bargain, these bags will rarely last you more than a year. I would try to save up for something with more substantial quality and good reviews (from actual divers).

Lightweight & Mobile

Frequent flyers will especially value a lightweight diving gear bag, probably around the 5- 9 pound range. Any heavier than that will put you over the weight limit on luggage once you add in your other tools and clothes. Mobility often translates to bottom rollers and a solid hand grip. Duffel or backpack style work equally well; it comes down to preference. Just remember, if your gear bag is truly mobile, you won’t even notice it (and that’s a good thing).

Solar Shield & Waterproof

Unless you keep your diving gear bag inside at all times, it’s going to receive plenty of exposure from the sun. Eventually, this exposure will cause your bag to fade in color and loosen the chemical bonds that hold it together. Especially along the zipper seams and pockets. It’s the same process that happens to carpet – ultraviolet rays smash against the chemical compounds, making it brittle (photodegradation).

Then there’s the water. Saltwater takes more of a toll than freshwater, but both can be problematic if your bag has constant moisture on it. If you can afford it, look for a gear bag that’s waterproof or water-resistant. There’s also smaller, less costly dry bags that can be used to hold your most precious personal items such as cell phones and watches.

The sun and water will be with you on all of your jobs, and no matter how high quality your bag is, you can’t stop the wear and tear it causes. Your best bet is to try to keep your bag in cool, dry places as often as possible.

2. Diving Knife

Photo Property of Venture Below

No underwater welder should jump into the water without one of these somewhere on their person. Diving knives serve a variety of functions, including cutting rope, wire and loosening rusted openings. And most importantly, you may use it to cut entanglements if your diver partner gets into a bind.

Straight and serrated diving knives exist on the market with everything in between. Each have their own uses.

Price $25 – 130

A mid-range diving knife should do just fine as long as you maintain it. Higher end knives may have additional features or include additional knives as a package deal.


Diving knives are composed of several types of metal alloys joined together. The strength of your knife is measured from how easily it breaks under pressure. Some knives have more “give” or bending ability, usually a sign of additional carbon mixed in.

Cutting Power

Many knives have sharp edges on either side. This trait is especially desirable in an emergency when cutting someone out of a mass of ropes or knotted umbilical cords, since you don’t want to waste time turning your wrist from side to side.

Find a knife that remains sharp even after continued use – check with the manufacturer if you’re not sure. No matter what you purchase, I recommend buying a knife sharpener to keep the edges properly aligned after each use.

Corrosion Resistance

Stainless steel isn’t immune to rust, but it certainly slows the rusting process. You’ll want a stainless steel knife that has an optimum balance of carbon, steel, nickel and other alloys in it. Look for a stainless steel grade of around 420. Then, along with sharpening, make sure you clean and maintain your knife after every use.


Every underwater welder has their own preference of weight, but in general, the lighter the better. Find a knife that has a solid feel in your hand but doesn’t cause arm fatigue over a 10 – 15 minute period. And look for some grip on the handle so that it won’t slip from your hand when using it. The softer handles work better, as you can squeeze in to create even more grip.


The sheath needs some resistance from saltwater also; some are made completely of plastic which works well. It should also easily attach to your body or in one of your diving suit pockets. And one of the best qualities of a sheath is its simplistic ability to hold and release your knife, so you may test this function above water. Practice by imagining you’re in a draw with a fellow cowboy across the room.

3. Dive Watch & Navigational Compass


Time and navigation can be the difference of life and death underwater. And though you should always be in touch with the surface, compasses can steer you in the right direction without visual contact. Watches are helpful during jobs that have short deadlines or limited equipment availability (for example, your company may rent underwater equipment for a limited time).


Watch: $50 – 1,500  |    Compass: $30 – 100

The quality of your watch and compass are most dependent on the type of protective cover, water resistance and gear inside. For a watch to be considered a “dive watch”, it must contain a water resistance level of at least 10 atm (atmospheres). This translates to 330 feet, or 100 meters below the surface.

Water Resistance

To help ensure a water resistance standard across the world, the International Organization for Standardization (ISO) has issued the following chart:

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In complete darkness, you still need a way to see the time on your watch or compass. Check for a display that lights up to illuminate all hands, notches and numbers. Examine the faces for easily distinguishable quarter segments (3, 6 9, 12 on a watch; north, south, east and west on a compass). The “12” and “north” should have the highest visibility. Pigments with solutions like luminous phosphorescent should already be applied to the dials so that you can see without using battery power.

Dive watch faces use three types of protective coating on top:

  • Acrylic glass – More easily scratched, but not easily shattered
  • Synthetic sapphire – highly scratch resistant; susceptible to cracking
  • Hardened glass – Medium scratch and hardness qualities

Watch and compass makers may apply anti-reflective coatings to watches and compasses to help view in shallow conditions.


Dive compasses are operational through magnetic forces alone, but dive watches are a different story. The primary functions include winding (if analog) and using the chronograph (stop watch). This video provides an overview of a few things to look for. The biggest takeaway? Watch “pushers” may create leakage.

Though dive compasses can’t be controlled since they work off magnetic fields, you should check for magnetic deviation before beginning your project. Deviation can throw off your navigational readings. High powered equipment produces electrical current such as a diver propulsion vehicle or nearby power lines. Also, don’t use your compass with magnetic tools in close proximity like a dive harness buckle or additional compass.


Both analog and digital dive watches are in the market. Old school divers prefer the analog versions for their mechanical characteristics and high dependability. Look for a watch with a power reserve indicator – this will tell you warn you that your watch is running on empty through either a flashing message or a 2 – 4 second jump of the second-hand on analog versions.

4. Underwater Light

Image credit: earth-touch, Flickr

Underwater welders often take an emergency air tank along with their surface air supply hoses, just in case their hoses malfunction. Similarly, it’s highly recommended to take both a primary and backup light with you for commercial dive jobs. Not only does it illuminate, but it can also signal other divers, the surface team and even scare off predators.

Price $60 – 200

If you see dive lights that cost $300 or more, they’re probably for camera work. Underwater camera lights have a wider beam and other attachment features you probably don’t need.

Power & Brightness

In the long run, rechargeable batteries are much more cost-effective and power efficient than their disposable brothers. Any light using 10 watts or more drains quicker than smaller, backup lights. Rechargeable batteries cost more up front but have a much longer life span. It’s best to keep at least one set of disposable batteries on hand, though, just in case the others lose their charge.

If you’re locked in a decision between LED or incandescent, I have two words for you: embrace technology.

LED’s are much brighter and efficient, and they’re here to stay. The only advantage of incandescent lights is its warm color when cast upon objects. A petty advantage if you ask me.


Primary lights come in a lantern or pistol grip types. The lantern grip gives more stability and is easier to carry for longer dive jobs. The pistol grip is best utilized for small, detailed projects with either a small area of focus or a wider atmosphere for a larger spread. You can also use mounted lights that attach to your dive helmet to free up both of your hands for work.

5. Underwater Camera


Underwater construction makes use of cameras quite often during the inspection stage and into repair. Both video and photo cameras are used. Training facilities have many cameras to record your work and demonstrate techniques that need improving. The majority of cameras are simply regular cameras inside of a waterproof case or housing.

Price $40 – 200

Similar to purchasing diving lights, this price range is a conservative estimate. Specialized underwater photography and videography bumps up the price into the thousands of dollars, but you don’t need something that fancy.

SLR Versus Compact

At the end of the day, this is the single most important question to ask.

Essentially, compact cameras are what you would think of as a “point and shoot.” Digital Single Lens Reflex (DSLR) have a complicated definition, but in general, they’re the cameras with removable lenses. I won’t go into detail on all of the characteristics, but here’s a few to consider.

Photo/Video Quality: DSLR’s dominate quality if you use them correctly. They allow you to manually control many features such as aperture, focus and shutter speed. Compact cameras allow for very little control, so your picture quality will suffer immensely if conditions aren’t good.

Size: Compact lives up to its name. Though larger with a waterproof housing, compact cameras are easy to carry and store in a suit pocket. DSLR’s, on the other hand, require two hands to use because of their bulk.

Weight: Again, compact takes the cake here. They weigh about half or less of what a DSLR weighs.

Zoom: DSLR lenses allow for a much tighter, more focused zoom. Compact can only extend to 2 or 3 times the original picture. On an underwater construction job, this probably won’t be an issue.

Case: For either camera type, you must have a case to house it in. Not all cameras have a corresponding case made for them, so you’ll have to pick and choose. Some are sold as a package deal, but most are apart from each other.

6. Diving Rope


What separates diving rope from other ropes? If you’ve been on a boat before, you’ve probably seen the ropes that they keep onhand. They’re completely synthetic so that no water is absorbed when put in the water. Underwater welders make use of rope in salvagery, underwater cutting and for projects where they must attach themselves to an object.

Price $15 – 250


Unless you really want attention, you’ll probably just purchase a blue, gray or green variety. But rescue ropes have bright colors, such as yellow or red.


If you’re connecting your rope to topside, you’ll need to take length into consideration. Saturation divers go a long way down. Otherwise, most standard length diving ropes will work just fine.

Tensile Strength

Rope strength is measured through pounds or kilograms of strength. If you’re salvaging extremely heavy pieces of metal, you’ll need multiple ropes that all have high strength. More strength usually means a larger diameter and more weight. Tensile strength may range anywhere from 1,000 – 70,000+ pounds.

Protective Coating

High-quality diving rope is protected from the water, sun, and electric current (dialectric properties).

The Favored

Divers that specialize more in HAZMAT or saturation diving may have a slightly different group of core equipment that they use on the job, but most will stick with these. They may appear small, but any one of these pieces of underwater welding equipment can make an enormous difference in carrying your projects out to completion.

You may also be interested in: 8 DIY Welding Positioner Plans You Can Assemble Yourself

Cameron Dekker

Cameron grew up in Allentown, Pennsylvania, a once-proud steel town on the Lehigh River, where he got a taste of TIG welding in his high school shop class. He holds certificates for Certified WeldingEducator (CWE) and Certified Resistance Welding Technician (CRWT) from the American Welding Institute. His interests include scuba diving, sculpture, and kayaking.