Your Scuba Gear


A mask is one of the most important, and personal, pieces of scuba diving equipment you own because it lets you explore with your eyes. More...


A snorkel is a very personal piece of equipment. It lives with your mask, spends time in your mouth, and lets you breathe while you look below, until you’re ready to submerge on scuba. More...


There are fins for swimming, snorkeling, free diving and body surfing. More...


Imagine scuba diving while hovering, weightless underwater – eye to eye with a fish. How is it possible? It starts with your buoyancy control device (BCD). More...


Most people float, which is great if you like to stay at the surface. However, scuba divers want to descend and need a weight system to help them offset this tendency to float. More...


If you think about it, breathing underwater is pretty remarkable, and it all happens because of the regulator. The scuba regulator is a great invention that delivers the air from your scuba tank to you just the way you need it to breathe. More...


Your SPG displays how much air remains in your tank so that you can end your dive well before you get too low. More...


You can track your dives using dive tables, a depth gauge and dive watch, but most scuba divers use a dive computer – it’s easier. More...


In the 1970s and 1980s, divers wore dive watches because it was the standard way to track bottom time while scuba diving. More...


A dive knife is a general tool that scuba divers occasionally use to cut entangling fishing line or rap on their tanks to get a buddy’s attention. More...


It’s obvious that a dive light is necessary to scuba dive at night to help you navigate, see your gauges, and observe interesting aquatic life. More...


Whether you’re driving to your local dive site or getting on a plane headed for the tropics, a sturdy gear bag will help you organize, protect and carry your scuba diving equipment. More...

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It’s called exposure protection because while scuba diving you’re not only exposed to water’s cooling ability but also to things that can scrape, cut or sting. More...


With the rise of digital photography capabilities, there are now numerous options for capturing images underwater. More...


An accessory is defined as an item that can be added to something else to in order to make it more useful, versatile, or attractive. More...


A dive flag indicates that scuba divers are nearby. In some areas, flying a dive flag while scuba diving is required by law, but in general it’s a good idea for safety reasons. More...


In the unlikely event that you’re at the surface and need to get the attention of someone on shore or on a boat, you’ll be glad you have a surface signaling device. More...


High-pressure cylinders are relatively small, yet very strong containers that hold large volumes of compressed gas. More...

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Technical (tec) diving involves diving beyond normal recreational scuba diving limits. More...


Scuba Tanks

High-pressure cylinders are relatively small, yet very strong containers that hold large volumes of compressed gas. Being able to carry your gas supply with you is what defines SCUBA (self containedunderwater breathing apparatus). Whether it’s filled with regular filtered air or enriched air nitrox (higher oxygen and lower nitrogen content) or trimix (three-gas combination) for technical diving, a scuba tank is one of the most important pieces of gear. Visit or ask Da Nang Scuba's experts to get advice about tanks.

Standard Scuba Tank Features

  • Cylinder made of either steel or aluminum alloy, although other composites are possible.
    • Steel cylinders are tough and resistant to external damage, but need proper care to avoid internal rust. They are negatively buoyant. The highest capacity cylinders are steel.
    • Aluminum cylinders are more susceptible to external dents, dings and scratches than steel cylinders, but better resist internal corrosion.
  • A valve controls the flow of air from the tank and connects to your regulator with either a DIN (screw in) or yoke (bracket) system. An o-ring seals your regulator to the tank valve.
    • Single tank valves, made of chrome-plated brass, are most common.
    • Technical divers may use dual-cylinder manifolds or use a Y-valves or H-valves  to connect two regulators to one cylinder.
    • Many valves have a burst disk – a thin copper disk – that will rupture, letting air escape if the tank pressure rises too high.
  • A current visual inspection decal shows that the tank has been professionally checked for internal and external corrosion within the past year.
  • Tanks require periodic pressure (hydrostatic) testing. The interval between tests varies in different regions ranging from two to seven years.

Optional and Desired Tank Features

  • A cylinder’s size and pressure rating determines its capacity.
    • Tanks from North America have capacities that range from 6 to 40 cubic foot pony bottles (reserve cylinders) to 45 to 150+ cubic foot main cylinders.
    • In metric system countries, cylinders range from 1 to 4 litre pony bottles (reserve cylinders) to 6 to 15+ litre main cylinders.
  • Tanks used with enriched air need to meet oxygen service standards and require distinct green and yellow markings to identify what’s in them. Interested? Take a PADI Enriched Air Diver course.
  • Cylinder boots – either plastic, vinyl or rubber – allow tanks with rounded bottoms to stand during storage and help protect surfaces from damage by tanks.
  • Other accessories for cylinders include mesh protectors that slide over the cylinder, valve covers that help keep water and dust out of the valve opening, and handles and carriers that make hauling your tank a little easier.

How to Choose Your Scuba Tank

Whether you own one tank, multiple cylinders or none depends on your dive activities and location. To select the right cylinder for you, think about size and capacity.

  1. Larger is usually better, unless you’re a smaller person and have to carry the tank a long way. Ask the dive professional at Da Nang Scuba's experts to get advice.
  2. Once you know the size you want, then choose steel or aluminum.
  3. Choose a yoke or DIN valve, based on your regulator.
  4. Think about a tank boot or mesh protector, and get extra o-rings.
  5. Make sure your new tank has a visual inspection decal, or an enriched air inspection decal (if you plan to use it for enriched air diving).

Take Care of Your Scuba Tank

  • Always block or secure your tank so it can’t fall over easily or roll around, which can damage it, other equipment or you.
  • Besides rinsing your cylinder and valve with fresh water and storing it in a cool place, don’t allow it to completely empty – always store it with air inside to keep moisture out.
  • Have your tank visually inspected annually and pressure tested as required.
  • Follow maintenance considerations according to the manufacturer’s instructions.