13 Tools on a Commercial Dive Boat and What Each One Is For

By Ray Whitfield, ADCI-certified commercial dive supervisor. Reviewed by Dana Whitcombe, technical reviewer.

Commercial Diving Contractors Alabama | Commercial Diving Contractors Alaska Thursday, 0630, on the concrete apron of the Pickens Hydro plant. Inflow was high enough to rattle the bulkhead, and the debris rack had a hole in it the size of a pickup truck. We had a 2,000-pound steel grate to re-hang in 40 feet of river water. That morning, my tender rolled his ankle on a stray coil of line and dropped the hydraulic coupling for the power unit into the river. No spare O-ring on board. We waited four hours for a part boat while the client stood there with a stopwatch. That was the morning I made the list. Here it is. These are the 13 tools I keep on the boat, every day, whether the job is a bridge pile inspection or a power plant intake overhaul. Some are for work. Some are for the moment the work goes wrong. And every one has earned its place with a lesson.

Talk and Breathe

Tool #1 is a hardwire comms box. There are a dozen brands, but the job is the same: a handset topside, a wire to the diver, and a speaker that lets you hear every breath. In zero-visibility water – the kind where you can't see your thumb – the comms box is your only eyes. You give the diver reference points, count turns, and talk him off a ledge when his line tangles. Tool #2 is the umbilical. It carries air, comms, and a pneumo line that tells you the diver's true depth. It's not a garden hose. It's a lifeline, loaded with a strength member and marked every ten feet. I tape the markers myself. The day you're in a pushy current and the surface gauge reads 35 while the pneumo says 52, you'll want those stripes.

Hydraulic Power and Cutting

Tool #3 is the hydraulic power unit. It's a diesel engine driving a hydraulic pump, and it runs everything that has jaws or teeth underwater. Fasteners shake loose, hoses sweat, filters clog. You treat it like a heart: check the oil, the pressure, and the relief valve. If that thing doesn't start, the rest of this list is just dead weight. Tool #4 is a hydraulic cutter. It's a pair of jaws that pinch, not chop. Rebar, cable, chain, a padlock the size of your fist – you clamp and squeeze. It's the tool you reach for when a derelict fishing net has wrapped around a dam stoplog, and the diver is tangled faster than you can think. Tool #5 is a hydraulic drill. Underwater, you can't just swing a sledge. You need a pre-drilled pin to hang a new intake screen, or a series of holes to sink a timber pile into a footer. The drill runs off the same power unit, and its only bad habit is binding when you push too hard. Let the bit eat. Tool #6 is an oxy-arc cutting rig. It's a hollow rod with a stick electrode inside, and it will burn through steel with the water boiling around you. Hydraulic cutters are quick, but oxy-arc is for when you need a controlled cut – like turning a large plate into two pieces that fit past a beam. It's a mix of oxygen and electric current, and it makes a noise you can feel through your boots.

Lifting and Rigging

Tool #7 is a pair of lift bags. They come in capacities from 500 pounds to 10,000 pounds, and they are the cheapest crane you'll ever hire. Fill one from a scuba cylinder or the surface air supply, and it takes a load off the bottom. Use two, always. Tie the tag line off to something solid; a lift bag that breaks the surface can turn into a rocket. Tool #8 is your rigging kit: shackles, wire rope slings, and a couple of soft nylon slings. I keep them in a canvas bag with the pin sizes written in paint. The only rule is inspect every time. A cracked shackle or a frayed sling is a diving accident waiting to happen, not a hardware problem. Tool #9 is the spreader bar. It's a piece of steel pipe with pickup eyes welded on, and it does one thing: it keeps two lift bags or two slings from pinching a load. Without it, your multi-bag lift turns into a wedge and the load shifts. With it, you're hanging a 3,000-pound object level. That's the difference between getting paid and getting sued.

Moving Water and Silt

Tool #10 is an air-lift. It's a long pipe with an air hose feeding compressed air near the bottom. The bubbles create a lower pressure, so water, sand, and small stones flow up the pipe and out the top. It's the best way to expose a buried pipe or clean out around a suction intake without a dredge barge. Keep the discharge down-current, or you'll be excavating the same hole twice. Tool #11 is a high-pressure water jet. It's a pump, a hose, and a nozzle that will strip barnacles and zebra mussels off a concrete wall. It also excavates soft clay or silt in an hour what a diver with a broom would take a day to do. The dangerous part is the kickback – hold it with both hands, and never point it at a diver.

Safety and Recovery

Tool #12 is a portable decompression chamber. Not every boat carries one – but if you're diving to 60 feet or deeper on air, you should. It's a steel tube with a door, a set of windows, and a lock that takes a patient in and the pressure up. It's also a rescue chamber. It can save a diver's life if he comes up with a bubble in the wrong place. I've used mine twice, and it earned its weight both times. Tool #13 is the emergency oxygen and first aid kit. The oxygen rig is a mask with a non-rebreather bag, and it's the first line for any suspected decompression issue. The first aid kit is standard – bandages, tape, antiseptic, a rescue blanket. But the key is to know where it sits on the boat and how to use it without thinking. The one tool that's never missing is the one you always replace.

Frequently Asked Questions

Do I really need a decompression chamber on a small workboat? If you're diving beyond 30 feet on air, yes. The chamber doesn't have to be big – a portable one fits on a trailer – but it's the difference between a close call and a fatality. I've seen a chamber pay for itself in two jobs. What's the most common tool failure you see? Hydraulic hoses and couplings. They get dragged, kinked, and left in the sun. A burst hose will take an hour to replace, but a failed fitting can lose you a whole day. I carry a spare hose and a handful of O-rings for every fitting on the board. Can I use a lift bag to move a boat off a rock? Not with a single bag and no rigging. You need at least two, plus a bridle, and you have to vent slow. I've watched someone flip a 22-footer with one bag. It's not a toy.