Scuba Diving Gear: What You Need to Think about before Choosing the Best One

If you’re doing scuba diving in the military, you’re amongst the best in the world. It’s not all planting mines on enemy warships and fighting with spearguns though. Most military scuba is checking the safety of vessels; looking for tampering or sabotage, repair work at depth, salvage, welding and cutting, surveying and disposing of underwater ordnance safely. There’s all the cool stuff like reconnaissance and search and rescue too. They get the best military-grade equipment and training. Exciting stuff.

Professional just means they get paid for it, but these are the guys ‘n’ gals who make it their lives’ work to scuba. Generally a dedicated bunch, they’ve dived everywhere and have the stories to match. Oil rigs, cargo boats, marine salvage, archaeology and scientific research, commercial and government contracts, mapping, building and even enforcing the law. To be a professional scuba diver you’ll need some serious qualifications and some serious kit, but once you’ve got them, the whole world opens up to you. Dive on wrecks: imagine finding cannons from the 17th century on the wreck of a pirate ship in the Bahamas, or ancient Roman triremes in the Mediterranean. Then imagine getting paid to do it!

The rest of us. The holidayers and the amateurs, the “once or twice a year with some friends” kinds of people. Not that it’s a bad thing! Scuba diving can take over your life, so for those of us that maintain a good work/life balance, recreational diving is just fine. You won’t be going much deeper than maybe 130 feet but the hours spent decompressing from deeper dives put most of us off anyway. Recreational divers should be able to make a straight, near vertical ascent at any time on a dive, that’s usually what the law requires. You’ve still got plenty of coral reefs, wrecks, rivers and lakes that you can explore to your heart’s content without getting serious. Always go down with a buddy or two and make sure your equipment is in order.

This is what you will have seen Jacques Cousteau and all your scuba diving heroes using. Using pressurized tanks of air, the system delivers air to your mouth and then lets it go bubbling off into the surrounding water. Depending on your experience with scuba diving, an open circuit system can last between 30 and 70 minutes on an “aluminum 80” cylinder, the more experienced diver being able to conserve more air. It’s a simple system, easy to get to grips with and reliable, it’s a go-to for many recreational and professional divers alike. Coral reefs, rivers and caves are all accessible with an open circuit.

How deep you’re diving, how long for and how experienced you are at scuba diving all affect what gas mixture you should use. Nitrox is a mixture of gases with a higher proportion of oxygen than atmospheric air. It’s a widely used gas mixture because it reduces the amount of time needed to decompress. The lower proportion of nitrogen means less is taken up by the blood and tissues. So when the time comes to surface, there’s less to come out and cause decompression sickness, or the bends. Potentially fatal, this is worth avoiding. Deeper dives might require a different gas mixture, like substituting helium for nitrogen or using a lower proportion of oxygen than air to reduce the risk of oxygen toxicity. Multiple gas sets and rebreathers (see the next bullet point) are often used for deep dives to provide the right gas mix at the right depth. It’s a dangerous business, diving. It’s crucial to get it right, so do your homework!

Sometimes called a closed circuit scuba, you’ll be as close to being a fish as you’re going to get; these devices take the carbon dioxide you breathe out from the gas mix and cycle the unused oxygen back into your gas mix. Instead of unused oxygen bubbling into the water, you use all you can before being forced to surface. They require some substantial training and experience to use but can extend a dive up to 240 minutes. There is a major drawback with rebreathers: your dive depth is limited to about 25 feet for a long dive as pure oxygen is toxic under pressure. This might be acceptable on a reef or other coastal feature, but most divers will want to go deeper, so might want to look elsewhere. That said, no other system can keep you under water for as long.

The speed of descent and ascent are crucial to a successful dive and indeed survival. Avoiding obstacles and getting out of the way of a mean looking ocean dweller is a skill that is fundamental to a safe dive. You’re balancing the upward force of your tanks’ and bodies’ buoyancy against your ballast weights, which sounds simple enough but can be a tough thing to get right. Buoyancy compensators (BC) are bladders that are filled with air to maintain neutral buoyancy underwater or to keep you on the surface if that’s where you need to be. If you’re carrying too much ballast (as many divers are), it can make the buoyancy trim difficult as more air is needed for BC the heavier you are. Shed any spare lead before diving if you can. Your lungs can hold a surprising amount of air, so if you have the habit of holding your breath while doing something complicated, you might find you got the trim all wrong when you breathe out, so relax. Your suit needs to be fully soaked before you adjust your buoyancy, so wait a minute or two in the water first. Your BC is using air you could breathe, be careful you don’t waste too much air getting your trim.

Finding yourself underwater, you’ll want to get around. The standard method is with diving fins. You’ll find yourself using muscles you never thought you had, so practice and orientation is a must before any serious diving can take place. When you get the hang of them they’ll feel like an extension of your body and you’ll be off! There is an enormous variety available, built for different size people as well as different tasks. Longer fins are good for gliding and distance but less good in a closer environment like a coral reef, where a short pair can help with the maneuverability you need to stay safe and off the sharp rocks. Ask around, everybody has an opinion on what’s best. Now, the really fun bit. Diver propulsion vehicles. Handheld propellers that will increase your range and speed underwater dramatically. They’re also totally James Bond. They can be picked up for a few hundred dollars or a few thousand if you like, it’s up to you. The more expensive end of the market will have better thrust and longer battery life, as well as higher reliability. They’re all huge fun though!

Waterproof LEDs are very useful even on daylight dives. Check out caves and stands of seaweed with confidence, and deter would-be predators with flashing lights. Let your buddies know where you are and keep tabs on them. Quite simply see what’s in front of you. Modern LEDs aren’t that power hungry, and batteries last a long time, but the prospect of going dark on a shark infested reef isn’t an attractive one, so keep ‘em charged! A spare battery pack in your group is a common suggestion. A good set of diver lights can help with your photography by being less startling to fish than a flash, they’ll help you frame and take your snaps too. Plenty of options out there, from tight beam handhelds to headlamps and shoulder mounted front and back lights.

Full face or just eyes and nose? These can vary from a whole face covering with an air feed so you can breathe normally and microphones for underwater communication to a simple eyes and nose mask. A snazzy mask with lights and all the mod cons can set your back some serious dollar, whereas for under 50 bucks you can get a perfectly serviceable mask that will take you anywhere. Yours truly has quite a lumpy head and so has to try on all the masks in the shop until he finds the right one. A tight seal that won’t stretch your face out or press your nose is what to look for. Strong, tempered glass is essential for scuba diving, as is a skirt around the nose to allow for equalizing as you ascend the surface. There’s the option of neoprene or silicone for the strap, silicone will hold better but is less comfortable than neoprene. Masks have different volumes too, a high volume mask gives greater visibility but is harder to clear than a smaller one. If you wear glasses prescription masks or optical inserts are available.

There are a few things to keep in mind while buying a wetsuit. Thickness increases warmth but reduces maneuverability, so it’s a trade-off. 5-7mm will protect against the coldest conditions (dry suits are better suited (sorry) to these conditions) but you won’t be able to move as freely. The style of suit is important, shorties are for warm water, mobile dives but not for anything at serious depth or temperatures. Full suits will take you almost anywhere but they’re heavier and can chafe more. Long johns are a compromise, your legs are covered but your arms and neck are free, so if you chafe badly around the neck or armpits they might be the choice for you. One style of wetsuit might limit you to one environment, so several might need to be purchased. Neoprene is comfortable and glides through water but isn’t that durable, so you might be back to buy a new one in a few years time.

A dry suit will take you anywhere it’s possible for a person to dive. The layer of air trapped between your skin and the suit, combined with warm undergarments, can keep you toasty and warm in the most adverse conditions. People dive in the Arctic with these things. Temperature loss is dangerous, if you get too cold you won’t be able to surface on your own. When diving in cold conditions, a dry suit is the way to go. By adding air to your suit you can alter your buoyancy, helpful if you’re having trouble with your trim. The downside to dry suits is the cost, they can set you back 3 or 4 times what a wetsuit will. That said, a well maintained dry suit can last as long as 20 years if well maintained. That means replacing seals, repairing cracks and keeping gloves and boots in good nick. Over the lifetime of a suit, it should pay itself off in terms of cost against a wetsuit, while letting you explore many more environments.

A good diving knife should be a few things, the first amongst them is sharp. Cutting ropes, stray lines or defending yourself against overly curious sea creatures shouldn’t be done with a blunt blade, it’s hard enough to move underwater. It should be long enough to be able to saw with and have a serrated part for cutting ropes. A textured rubber grip will stop it slipping from your grip and disappearing into the murk. A lanyard or tie string can keep it from getting lost. The sheath needs to be in a place where it can be drawn easily and put back without puncturing your suit by accident. Line cutters are a very handy tool to keep on your D-ring, getting snagged can be very dangerous. Knives should be marine grade stainless steel or titanium (the more expensive and harder to sharpen option). Be sure to clean your knife (as with all your kit) as salt water will corrode even the most stainless of steel.

Essentially a spare air canister, this can make the difference between surfacing and not. Even the most experienced divers can run out of air through a leak or faulty equipment. A spare, redundant system that isn’t affected by whatever fault might have emerged in your main system should be standard kit on any dive. Hands free when in use, a spare air canister can be mounted on your chest for easy access in an emergency and connected to your BC easily. They are refillable and reliable technology. You might save your own or your dive buddy’s life with one of these, so it’s a great investment. Hopefully, you’ll never have to use one.

I have nightmares about losing the boat and surfacing in the blank, featureless ocean with no hope of rescue. I shouldn’t have watched that horror movie I know, but it’s a real concern. This is why surface marker buoys, or SMB’s, are essential to any dive. They link you or one of your buddies to a surface buoy that lets the safety boat know where you’re diving. It’s not at all difficult to get caught in a strong current or get carried away looking at the pretty fishies and find yourself a long way from your buddies. With an SMB your boat will be able to cruise along and pick you up, even if you get yourself totally lost. They can act as a depth reference as well as telling your safety boat when you’re about to ascend.

It’s my nightmare again. Come to the surface to find nobody there to pick you up. Your body temperature is dropping, it’s getting dark and there are pointy fins in the water. What do you do? Calm down, slow your breathing and activate your PLB/EPIRB. The emergency services will know where you are and dispatch a boat or helicopter to pick you up. They can communicate with your safety boat and have you safe in no time. It’s one piece of kit that you hope you’ll never have to use but always want with you. 99% of EPIRB signals turn out to be false but over 20,000 people have been rescued since the COSPAS-SARSAT system was set up.

A torch is a must, as is a noise maker. Sound travels much better in water than light so an acoustic signal is a pretty good way of getting your buddies attention in low visibility. A squeezable (no batteries to get wet) horn can be heard from a long way away. Octopus rigs have saved countless lives by enabling another diver to use your air supply. Small and portable, pack one. Most DC’s are computerized, so what to do if it crashes? Carry a spare. A wrist mounted compass will keep you orientated at any depth. A whistle will stow away nicely and tell anyone up to half a mile away where you are. A flotation device can keep you above water even when you’re exhausted. A small canister of water dye will make you much more visible to any passing aircraft, as will a flare. Glow sticks last a lot longer than flares and work even when wet, so are worth finding space for.

Don’t go anywhere near a dive without these, you’ll put yourself in serious danger. Get yourself a digital depth gauge, it’ll tell you very accurately how deep you are, as well as conditions like high pressure zones and temperature. A diving watch with a big, clear, illuminated face is not only totally cool but a very practical bit of kit. If you don’t know how long you’ve been underwater, you’re screwed. And a compass, any navigation, at sea or on land, requires orientation. If you know you came south then you should be heading north to get back. Sometimes survival is as simple as that. Map reading is difficult underwater, so a big compass that’s easily readable and accessible is a must.

This will track your oxygen levels, pressure, depth and time underwater to put together an ascent profile to help a diver avoid the bends on the way up. If you’ve switched gas during the dive some dive computers will factor this in. It all makes for much easier ascending. The computer will tell you when to ascend and how fast. Some will have audible alarms if you’re passing a no-stop limit or the maximum depth for that gas mixture. There’s no need to take decompression tables with you, the computer can load your body profile and show you when to make adjustments to your gas mix and depth.

An essential tool on any dive, you’ll need a diving reel to find your way back out of a wreck or difficult bit of reef, or connect you with your buddies/safety boat. The ocean is a big, disorientating place, that yellow line stretching back towards to the surface is not only comfort but good navigation. Find your way home. Diving reels are a very simple bit of kit, they’re just a spool of strong wire or rope you can tie to whatever you need to get back to, like your SMB, that interesting rock or the rendezvous point. Keep them taught at all times and don’t ever attach yourself to a tied diving reel as that could trap you.

The first thing a diver wants when they get out of the water is a drink. But after that, dry clothing is usually on top of the list. Warm up and feel comfortable. But it’s been choppy and all your clothes are soaked and freezing cold. That’s a perfect recipe for misery. That’s why every dive boat has (or should have) at least one dry box or bag. Stick your clothes, food, delicate electronics in it and rest assured they’ll still be working after the dive. Small, waterproof bags can keep your smartphone or camera dry at surface pressures but don’t take them deeper. Otherwise, keep your dry bag on deck. Large cases with airtight clasps can fit in lots of sensitive equipment and woolly socks, smaller ones are good to have at hand for your GPS or camera for quick access.

Want to know how deep that chasm is? Whether you have the gas and time to get down there and up? Send an acoustic “ping” off the seabed to accurately gauge the depth you’re swimming in. You could be plotting out a future dive or mapping, or just want to know how deep the rabbit hole goes. Sound travels at a set rate under water, so by measuring the time it takes a signal to get from your echo sounder to the floor and back, the machine can work out how far away something is. Don’t worry, you can’t hear it, though it might make some of the local dolphins curious.

If you know where you are when you dive and when you surface, you’re doing the right thing. A GPS will tell you to within a couple of feet where you are on the surface (they don’t work underwater!). This might be some way from where you started, but at least you know that and can radio the safety boat to come get you. If something bad happens and you need to surface quickly to radio for help, you can save precious minutes by telling the coastguard exactly where they can come to help. If you find something cool on a dive, you can just pop up a buoy over its location and later on go and mark down its coordinates for future exploration. Make sure yours is waterproof, buoyant and brightly colored so you can easily find it. A rescue GPS is worth every cent in a jam.

This is the stuff that could be handy but isn’t essential to own. You can get your bottles filled at nearly any harbourside in the world, so buying your own compressor might not be necessary. If you’re doing a lot of diving and don’t want to head back to land every day for more gas, a compressor could save a lot of money and time. Darn convenient having one around as well. You’d do well to have a spares box, get some regulators, octopuses, torches, clothes, masks, dive computers, suits, spearguns, tanks and fins on the cheap and keep them somewhere safe. A whole dive can be halted just for the need of one little gadget, so it’s worth having a spare or two.