Diving equipment – GearGuide


Every part of the diving equipment plays an important role. That is why you need to know how to use and maintain the parts of the equipment in the right way.

In this section you will learn the basic diving equipment and learn how to contribute to the safety and enjoyment of your diving experience.


  • Trim vests
  • Diving suits
  • Fins
  • Masks
  • Snorkels
  • Lead (belts)
  • Instruments
  • Surface markings
  • Regulators

Trim vest

Mares-Hybrid-MRS-ATThe BCD, also known as Bashjacket or BCD, is an important part of diving equipment. Divers use the BCD to stay at a certain depth and to control the buoyancy during the descent and ascent.

Image: Mares Hybrid MRS+ AT trimvest


Parts of a Trim vest

  • Inflator: A low pressure inflator, also known as power inflator, is connected to the regulator to transport gas from the diving cylinder and the regulator to the trim vest.
  • Bladder/air chamber system: This can be a single-bladder or a double-bladder. With a single bladder, the air chamber functions as the air reservoir and as the casing, while with a double bladder only the inner chamber is filled with air. The diver can let air in or out of the bladder to adjust its buoyancy, allowing the diver to move more easily under water.
  • Pressure relief valve: This part bleeds the leaves when the diver has let too much air in the barge during the descent.
  • Inlet valve: This valve transports the gas from the inflator to the bladders of the BCD.
  • Breather valve: This allows the diver to run gas out of the bladders of the BCD.

Kinds of Trimvests



These are trim vests with the bladder on the back and on the sides. They are widely used by divers who are engaged in underwater photography and technical diving. The wings are attached to the backplate, which is attached to the diver. One of the characteristics of this type of BCD is that the bladder is not at the front of the body, leaving room for other equipment that the diver may need.

Vests / Jackets

These are inflatable trim vests, which can give buoyancy up to 25 liters. A diver wears a Jacket around his upper body.

Life jackets with adjustable buoyancy

These can give a buoyancy of 15 litres. They are cheap and lightweight. The disadvantage is that they are not comfortable since this type is worn around the neck and is fastened between the legs.

Guide to Buying Vests

  • Know which type suits you best. For beginners it is advisable to wear the jacket model.
    You will wear your BCD during the entire dive, so it is important that you choose one that is comfortable. In addition, you must ensure that he has the right size for your body.
  • Try to adjust a fully inflated BCD. This way you can check whether the BCD does not interfere with your breathing.
  • Some models have buckles at the shoulders. This makes it easy to put on and take off your BCD.
  • Trim vests are very important when diving, so make sure you know how to use a bobbin properly and how to maintain it.

Diving suits

scubapro-everflex-5-4-mm-back-zip_1The diving suit is another important part of the diving equipment. It is intended and designed to protect your body against hypothermia, animal bites, and cuts and abrasions while diving. In general, it just works the same as your everyday clothing. A big difference, however, is that you use it in a different kind of environment. One of the characteristics of a diving suit is that it is able to protect you from hypothermia when you are under water. This is important, because as mentioned elsewhere, water absorbs body heat faster than air.

Image: Scubapro Everflex 5/4 mm back-zip duikpak (wetsuit)


Dive suits come in three standard types: a tropical suit, a wetsuit and a dry suit.

Tropical suit

This suit is lightweight and made of nylon and lycra for elasticity. It offers only some thermal protection, making it especially used when diving in warm waters. In addition, it offers a lot of freedom of movement. However, tropical suits are quickly damaged by friction and when diving in places with constant bright sunlight.


A wetsuit is made of neoprene, which makes it elastic and makes it easy to pull on and off. Wetsuits are available in different thicknesses. The thicker the wetsuit, the more heat it gives. Moving, however, becomes more difficult, since a thick wetsuit is stiff. On the other hand, although you can move more easily in a suit that is less thick, this will give you less thermal protection compared to a thicker wetsuit. What you choose depends mainly on the conditions under which you dive.

In addition to the thickness, wetsuits are also available in different models. A ‘shorty’ covers only your upper legs and upper body, while a ‘long john’ covers you from just under your shoulders to your ankles. You then wear a long jacket with a zipper, which serves as a second layer for your upper body.

Make sure you maintain your wetsuit well. Wash it with clean water after each dive. Turn the inside out, hang it to dry and prevent wrinkles.

Dry suit

Duikuitrusting-Duikpakken-Bare-CT200-Polarwear-ExtremeThis type of diving suit covers your entire body. It is widely used in diving under very cold conditions, as dry suits enable the diver to wear warm underwear.

Image: Bare CT200 Polarwear Extreme dry suit


A property in which drysuits can differ from each other is the material from which they are made. A membrane dry suit is made of a trilaminate of nylon, butyl rubber and nylon, or vulcanized rubber. It has a protective layer that ensures that the water can not enter the suit. However, it can not keep you warm, as it has no insulating properties, so you have to wear warm underwear.

There are also dry suits made of neoprene. This material does have thermal insulation properties. The disadvantage of this type of drysuit is that as the diver descends deeper, the neoprene is compressed, leading to loss of insulation and buoyancy. That is why a modern drysuit has a valve, with which the diver can regulate the buoyancy. With the help of a low pressure inflator, this built-in valve allows air to run into the suit.

Knowing the different types and characteristics of diving suits makes it easier to determine what you attract during your dive. Take into account a few factors, such as water temperature and location. The most important thing is that your suit does what it has to do: give you protection and comfort under water.



Scubapro_Spectra_Metallic_Black_Skirt_-_BlackA mask protects your eyes and allows you to see underwater. It ensures that there is an air-filled room in front of your eyes, so that you have clear vision during the dive.

Image: Scubapro Spectra mask

As the pressure increases as the diver descends, the mask must be made in such a way that there is enough space around the nose so that the diver can pinch his nose to clear his ears. In addition, he must be able to breathe through his nose into the mask in order to keep the space in front of his eyes filled with air during the entire dive.

Parts & properties

A mask is indispensable, to ensure that there is an air-filled room in front of your eyes during the dive. This gives you a clear view underwater. Masks come in various shapes and sizes, and with the help of technological developments, manufacturers always come up with new models with modern features and modern design that meet the requirements of the divers. But however advanced masks may be, it is important to know how they work. This can be achieved by learning the various important parts and characteristics of masks:

Mask band

This holds the mask in place while diving. The strap prevents the mask from being knocked from your head.

Durable glass lens or plate

The lens creates a flat window or screen, allowing us to look through water well. Most masks have a flat lens to prevent the light from being distorted by water and/or air. But there are also modern models with a convex lens.


This is the soft, flexible part that has been designed to fit your face. It ensures that the space in front of your eyes stays filled with air during the entire dive and that no water flows into the mask, by properly closing the space between the lens and your face.

Cut out for the nose

This section allows the diver to breathe through the nose in the mask.


This section holds the lens and the edge together.

Know the essential parts and characteristics of the mask, so that you can use it to the fullest when diving.

Buying guide for masks

Masks are available in different shapes and sizes and with different properties. As time goes by and the technology evolves, new models are introduced with modern features and modern design to meet the requirements of divers engaged in various diving specializations. A buying guide can help you reduce your options.

In this section you will learn more about what to look for when buying a mask:

  • Comfort and fit are very important when choosing a mask. These are some guidelines for fitting a mask:
    • Keep your hair out of your face.
    • Place the band on the back of your head and then pull the mask over your face.
      Make sure the edge is not wrinkled. The mask must close properly – with a wrinkled edge this does not work.
    • Breathe in through your nose. The mask fits if you do not feel air or hear escape.
      Pay attention to the edge. It can be made of silicone, plastic or rubber. Silicone edges are preferred because they are better sealed than edges of another material.
    • Choose a mask with a small air space. With this type of mask there is only a small space between the lens and your face. This also means there is less room for water, making it easier to clear your mask.
    • Make sure the lens is made of tempered glass, or that it is a lens where no small pieces can shoot into your eye if it breaks during diving.

Know how to buy a mask. Try on several masks and choose the one that meets your diving requirements most.

Maintenance of your mask

Wearing a mask is very important for a clear view underwater while diving. So you have to maintain the mask well, especially when you are not using it. You do not need special skills to keep your mask in good condition. Just make sure you do not neglect the mask.

In this section you can view some tips on how to properly maintain masks:

  • Be sure to rinse the mask with clean water after use to remove any residue left after a dip in salt water from the mask. Hang the mask to dry, but not in direct sunlight. Make sure it is completely dry before you store it.
  • If you keep covering your mask, buy a special anti-fogging agent. Apply this to the inside of the lens and then rinse thoroughly.
  • Avoid scratching your lens by always putting the mask down with the lens upwards.
  • Store the mask in a cool, dry place after diving. Stop him preferably in his own box.
  • Do not place heavy objects on top of your mask.
  • If you descend during your dive, make sure you clear your ears enough. Otherwise, your mask will be pushed against your face by the increased water pressure, which feels uncomfortable and can even lead to broken blood vessels in your eyes.

Generally speaking, you only need your common sense. Make sure that you maintain your mask in the right way, so that you can use it to the fullest extent while diving.


sp_snorkal_spectra_white_2491Another essential part of the diving equipment is the snorkel. A snorkel is actually nothing more than a hollow curved tube made of rubber or plastic with a mouthpiece that allows you to breathe when you swim on the water surface with your head just beneath the surface of the water. In other words, one end protrudes above the water while you have the other end in your mouth. The snorkel is attached to the strap of your mask with a clip. A snorkel is useful for diving when you need to save breathing air.

Image: Scubapro Spectra snorkel

A snorkel is on average about 30 centimeters long and the maximum length is 45 centimeters. Breathing is easiest with a snorkel with an inner diameter of 2.5 centimeters. There are also snorkels with a waterless valve. If you use this type of snorkel, you will have virtually no water in your mouth during the dive. The waterless valve helps you clear the water from your snorkel. Another type of snorkel often leaves a small amount of water in the mouthpiece, which is not inhaled during breathing.

How to use a Snorkel

  • Put on both your mask and your Snorkel to check the fit and see if they are comfortable.
  • Attach the clip of the snorkel to the strap of your mask.
  • Adjust the snorkel so that, if you have the mouthpiece in your mouth, it is up at the height of your crown.
  • Take a deep breath. Put the mouthpiece in and then go under water.
  • Clearing – Breathe out once to make sure that the air passage is not blocked.
  • Carefully move under the water surface so that no water enters the snorkel. If this does happen, empty the snorkel.
  • Emptying – Make sure the end of your snorkel is above water. Hold the mouthpiece firmly in your mouth and blow or breathe hard to remove the water. Gently inhale in case there is still water in the snorkel. You may have to empty your snorkel several times during the dive. This depends on the swell of waves and your movements under water.

You will need a  snorkel with the right length for you. You can breathe normally if you use a relatively short snorkel. However, it must be long enough that one end remains above water when you go underwater with your head. Another important aspect is the fit. Make sure you use a comfortable snorkel that does not affect your breathing.

Although a snorkel is a fairly easy-to-use part of the diving equipment, you have to reckon with the fact that there are a number of factors that you should pay attention to when it comes to your equipment. Get used to breathing through a snorkel, for your own safety and fun in the water.

Diving Fins


Fins are an essential part of your diving equipment. They are fin-shaped shoes, which are usually made of rubber or plastic. They help divers to propel themselves underwater with less effort. With water sports such as diving, the fins should have the size and characteristics that are appropriate for your body.

Fins are of great importance when moving underwater. They come in different sizes, colours and shapes. Some divers may prefer modern Fins with additional features, while other divers choose the traditional fins. Whatever your preference is, make sure that a comfortable fit is much more important than what the fins look like.

Types of fins

There are two standard types of fins: with open heel and with closed heel.

Fins with an open heel

open-heel-finThis type, also called adjustable strap fins, has an adjustable heel strap to hold them in place. They are usually used for diving in colder water. You need special diving shoes to use this type of fin. However, they offer less protection for your feet and the tires can rub along your heels, which gives an uncomfortable feeling.

Fins with closed heel

full-foot-finWith this type, also called full foot fins, you do not need diving shoes. In general, this type is cheaper and they are very comfortable, provided you have found the right size. The most important thing to watch out for is the fit. The fins should not be too tight, nor too loose. Too tight fins can pinch the blood supply to your feet, while too loose fins can easily shoot off your feet when you go into the water. Make sure they sit comfortably, closely around your feet, but in such a way that you can still move your toes.

Power Fins

power-finThere are also so-called Power Fins. There are openings or slots in the blade so that moving through the water is more efficient.

Force Fins

force-finAnother model of fins are the Force Fins. These are smaller compared to the other models. They offer an efficient thrust, comparable to the operation of the relatively small tail of a whale.


suunto-cobraIn order to experience a safe and enjoyable diving adventure, there is a long list of things you need to know and keep an eye on when you are underwater. Modern technology makes it possible to determine such things as depth, pressure and dive time using various instruments, such as a depth gauge, a manometer, a dive computer and a diving watch.

Image: Suunto Cobra

Other tools and instruments, such as a knife and diving compass, can also come in handy. These parts of the Diving Equipment are very important during diving.

In this section you will learn more about the different instruments needed for diving:

  • Depth gauges
  • Manometers
  • Diving computers
  • Diving watches
  • Knives
  • Dive companions
  • Depth gauges

Depth gauge

This instrument is used to determine the maximum depth achieved during the dive. Modern depth gauges also indicate the fall and ascent rate and guide the diver with this, so that barotrauma and other pressure-related disorders can be prevented.


This instrument is used to determine the amount of air remaining in the dive bottle (the cylinder pressure). It is attached to the high-pressure port of the first stage.

Diving computers

A dive computer, also called decompression meter, is an electronic device that helps the diver to identify important information such as the current depth, dive duration, maximum depth reached, no-stop time and water temperature. There are also Dive computers that give an audible warning signal in certain situations, such as when your rate of ascent is too high or when you have exceeded the maximum dive depth.

Dive watches

Duikhorloge-Suunto-DX-ElastomerThere are watch models that are specially designed for use underwater, up to depths of 60 meters or more. It is better if your watch has an illuminated display so that you can use it at night or in low light.

Image: Suunto DX Elastomer

Nowadays diving watches are commonplace. The dive computer has a separate mode for Air / Nitrox, Apnea / Measurement. It gives you all the information you need during diving, such as complete information about the decompression stops.


duikmessen-seac-bc-jackAls je onder water bent, kun je verstrikt raken in vislijnen, visnetten, touwen en zeewier. Je hebt een mes nodig om jezelf los te kunnen snijden uit dit soort dingen, om gevaarlijke situaties te voorkomen. Bovendien kun je het mes gebruiken om de aandacht te trekken van je buddy en andere duikers door ermee op een Duikfles te slaan in geval van nood.

Image: Seac BC Jack diving knife

Diving compasses

This comes in handy with the underwater navigation and when changes occur in the environment that reduce your view, making it harder for you to orient.

With the exception of the knife, these are all electronic devices, so in the worst case there is a chance that they will fall out. That is why you must check before the dive that all the instruments are working properly. Carry out the necessary preparations and safety measures so that you can experience a diving adventure without danger.


People have a higher buoyancy in salt water than in fresh water. Your diving equipment also affects your buoyancy. We all know that maintaining the right buoyancy is very important when diving. The use of lead and lead belts can help you achieve a neutral buoyancy so that you remain under water.


Most lead consists of rectangular blocks or cylinders with rounded ends, weighing 1 to 2 kilos. A weight belt is usually 5 centimetres wide, made of nylon and holds the lead in place around the plunger’s waist. The belt has an adjustable quick closure so it always fits well. In addition, a weight belt has clips to hold the lead blocks in place and ensure that they do not come loose during diving. There are also weight belts with shoulder straps for extra support.

View some standard lead systems when diving:

Soft lead belt

Lead pellets are held in place by built-in bags in the belt.

Lead belt with lead blocks

As the name implies, this type of weight belt consists of a belt, to which lead blocks and a quick fastening are braided.

Trimvest with integrated lead

The lead is integrated into some types of trim vests.

Lead can, in addition to helping to maintain the correct buoyancy, also act as a means of rescue when diving. The lead can be thrown off to increase the buoyancy when the situation requires an emergency rise. That is why it is very important to know the mechanism of your own weight belt and that of your dive partner.

Make sure that you, as part of the buddy check, both know how to loosen the weight belt and how you can add or drop lead, especially in emergencies. If your buddy wears a weight belt with shoulder straps or a harness, make sure that you know how to disconnect before the dive.

Surface markers

One of the safety measures when diving is to ensure that people on the water surface know that divers are present at a certain location. There are tools for this, which can be used to indicate where the diver is during the dive or during a decompression stop. In addition, you need tags that ensure that the boat can keep an eye on where the divers are during the dive. The parts of the diving equipment that provide these kinds of important items are called the ‘surface markings’.

In this section you will learn more about the functions of surface markings, such as marker buoys, deco-buoys, diving buoys, dive flags, darkening fluids and whistles.

Marker buoys or SMBs

A buoy is a floating object that can be used for many purposes. When diving, a marker buoy, also called Surface Marker Buoy (SMB), consists of a buoy with a solid thin line, wrapped around a reel and attached to the diver. He is blown up before the dive. This buoy ensures that the boat on the water surface knows where the divers are. In addition, pulling hard on the buoy line is a way of communication between the crew of the boat and the divers under water. Marker buoys are usually used for current diving and night diving. They are also used when there is poor visibility or strong currents.

It is better to use only one marker buoy per dive, as divers can get entangled in the lines if multiple marker buoys are used simultaneously.

Deco buoys

Deco buoys, or decompression buoys, are inflated under water to mark the position of the diver when he holds a decompression stop. This allows the boat to locate the diver more easily. A line connects the deco buoy to the water surface with the diver under water.

As a safety measure, every diver is obliged to have a deco buoy with him, in case the divers are separated.

Diving buoys or floats

A dive buoy marks the dive site and ensures a safe descent and ascent for the divers. It consists of a weight, a float and a line. The line has many functions: for underwater navigation, for controlling buoyancy and for performing decompression stops in strong currents. Diving buoys are often used when there is poor visibility.

Diving flags

In diving, the generally accepted dive flag is the signal flag A of the maritime International Signal Book. This is a blue-white flag with a dovetail. Another dive flag is a red flag with a diagonal white stripe. The Dive Flag must be placed in a prominent location. It must be clearly visible and not withdrawn from the sight of other vessels. When a boat feeds the dive flag, it informs other boats that there are divers under water and that they have to slow down or have to race around the dive site.

Marking fluids

Bright dyes (orange, for example) are used to increase the visibility of the divers from the air. Marking fluids color a large part of the water surface, making them clearly visible to rescue helicopters.


The use of a high-pressure horn is an effective way to attract the attention of the boat on the water surface. Be careful in the use of high-pressure bells. They produce a deafening sound, so keep them away from yourself and other divers.

Without these ‘surface markings’ it is very difficult for the boat to keep an eye on the position of the divers. And you should not think of it as a diver that after the dive you reach the water surface again and see that the boat is very far away, or worse, that he is completely nowhere to be seen.

Make sure you know the functions of the various surface markings during diving. Use these tools when needed. Even if you are not a diver, it will be useful to know something about these surface markers and the signals used in diving.


Marys-Abyss-22-Navy-Scuba-Diving-RegulatorPart of the diving equipment is the regulator, also called ‘relaxer’. This regulates the amount of breathing gas supplied during the dive from the diving bottle to the diver. The regulator reduces the air pressure of the breathing gas in the flask to an inhaling level for the diver.

Image: Mares Abyss 22 Navy regulator


Here are some important things to know about regulators:

  • A standard regulator consists of two stages with a single hose. The hose forms the basis of the air supply, while the presence of two stages means that the pressure in the diving bottles is reduced in two steps, in order to reach the right pressure at which the diver can breathe in the breathing gas.
  • The first stage consists of a valve, which reduces the pressure from the cylinder from 200 bar to a pressure that is higher than the surrounding pressure on the lungs under water (10 to 13 bar).
  • Then the valve in the second stage transports the gas from the hose to where it should be.
  • Second stage with automatic valve – This has a low-pressure hose that runs over the diver’s shoulder. There is a water release button on the front that opens the valve, allowing the air to flow unhindered and flush water from the second stage. The exhalation valve at the back leads the air bubbles away from both sides.