TRUNKDIVERS


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Night diving.
Although night diving is a regular part of the advanced course (not at some organizations anymore), it is well worth a specialty. Night diving is much more than just diving with limited visibility. The night dive in the advanced course should therefore be seen as an introduction. The night dive specialty covers all aspects of night diving so that divers can safely dive at night.

The difference.

Diving in itself is a great experience. Night diving is an extra addition to this experience. The underwater world changes during the night, different sea creatures emerge and the appearance of various organisms changes. Although there is limited visibility with night dives, you often see more than with a day dive. The reason for this is that you look more closely and the view is limited to where your lamp shines. Never swim fast on a night dive.

Lighting.

There is a wide choice of underwater lamps. The advice is to take a powerful lamp and a less powerful (therefore cheaper) lamp as a spare. A lamp must be easy to use and have a good grip, possibly also with gloves. It is useful if the lamp is provided with a cord with which you can attach it to the vest or the wrist. Do not forget to replace or recharge the batteries.

Light rods, so-called “breaklights” are also available. These are filled with a chemical and a glass tube. If the glass tube is broken, the rod will emit light for a few hours. These rods are disposable and are ideal for attaching to tanks, buddy teams and points of interest or danger. They are also very useful as edge marking. Break lights are a good addition to safety.

There are also various safety lights for sale, some are for single use. Always check the expiration date of such lamps. The image on the left shows a so-called Jotron. This is not a dive light but a flashing light.

It is also wise to take a light with you during every dive. An afternoon dive that doesn't go according to plan can end in darkness. You can attract attention with a lamp.

In addition, a mask with integrated lamps. Handy because you keep your hands free. The disadvantage is that if you look at your buddy you will immediately blind them.

Temperature

During night dives, divers can get cold more quickly. Make the dive a bit shorter than during the day. Another option is to use a thicker wetsuit. There are also so-called sharkskin suits available that can be worn under the wetsuit. A hood and gloves can also keep you from cooling down.

Compass.

It is easy to get lost or disoriented on a night dive. A compass can contribute to safety. It is recommended to always bring a compass with you on a night dive.

Dive knife.

A diving knife for a night dive is recommended. Fishing wires and the like are more difficult to see than during the day. Using a knife with night diving is more difficult because you usually already have a light in one hand. Using both hands then becomes difficult. The help of a buddy is sometimes necessary. Make sure the knife is sharp and preferably fitted with a wire cutter. Provide a wire to the blade to avoid losses. A brightly colored knife is preferred.

How to use the dive light.

Move your lamp slowly and with regular movements.

Avoid shining in the face of other divers.

When you see something interesting, circle the object. The buddy does the same to indicate that he / she has seen this. Repeat this signal for any subsequent divers.

To attract attention you can move your lamp quickly, best by the light beam of the person whose attention you want. If you have the attention, point to the object.

The OK sign is given by making a slow circle with the lamp. This works well with groups, every diver has to repeat the signal. In small groups you can give the normal OK sign and shine your hand with the lamp.

When one, with a group, goes to the surface, or wants this to happen, move the lamp from bottom to top, at a slow pace.

In case of problems, you can hold the lamp against your chest so that the upper body and head are illuminated, then you can point out the problem, such as ears.

Entering the water.

It is usually better not to turn on a light when entering the water. As a rule, diving takes place at a known place during the day. Your eyes can get used to the darkness and you save batteries. Another point is that, just like rabbits in headlights, some sea creatures “freeze”, causing you to step on them, for example. As soon as you go down turn on the lamp and shine down to prevent damage to the coral. Light up your watch and console, they usually stay lit for a while.

Leave the water.

When leaving the water a light can easily be damaged, to keep your hands free you can attach it to your BCD. When you take off your set, make sure your lamp does not fall on the floor. Dive lights are usually fragile and the slightest damage can break the light under pressure. After the dive, remove the batteries. Dive lights are made for underwater use. Avoid use as "regular" flashlights.

Warning.

During some seasons there may be jellyfish, such as Portuguese warships. You can shine your lamp over the surface of the water to see them. Occasionally look out in front of you instead of down.

Underwater life.

Normally you will see many different types of marine life during night dives. You can usually get close. avoid dazzling sea creatures, they can crash. Coral is very beautiful at night with a diversity of colors. Many flower-like corals and plants only emerge from their shelter in darkness.

Fish and other animals.

Avoid dazzling marine animals. At first they will “freeze” but eventually they will want to flee. Marine animals can crash if they, at full speed, swim against the coral (or a diver). Some fish, especially parrot fish, protect themselves at night by making a cocoon. This “sleeping bag” consists of proteins and can only be made once every 24 hours. When these fish are disturbed, they become “prey” by predatory fish all night, with all the stress that this entails. Never shine directly on (these) animals. You can also see these fish well in the “scattered light”. You can point them out by outlining a large circle and then simply pointing a finger or hand.

Fear.

Some people are afraid of the dark. In night diving, one can imagine all kinds of things that could happen, such as:

- Shark attacks. The risk of being attacked by a shark or other predatory fish is significantly less than the risk of driving to the dive site.

The risk is in any case less for a diver, even in daylight, than for a snorkeller, surfer or swimmer. Sharks come to flounder, this only happens on the surface.

It is not uncommon for imagination to play a major role in the development of fear. A small fish in your beam can cast a terrifying shadow. If that shadow falls on moving coral or plants, it just seems like a real threat.

If people (or yourself) are anxious or nervous, have them swim “inside the reef” or, if not possible, have the divers in question flanked by experienced divers.

Focus on the bottom and the surrounding area, shining in the darkness makes little sense. Especially when you recognize that you are actually looking for things that are not there.

Some people get scared of the nightly “black” sea. Still, people can regularly see well under water in darkness, it said in black and white. The phenomenon is the same when someone looks into the garden from an illuminated living room. It is then difficult to distinguish anything. When you walk outside you can see quite a lot in the dark. With a full moon you can, on Curaçao, look up to 20 meters depth without a lamp.

Buddy check.

This should of course happen with every dive, but with night diving there are a few extra points:

Test all lamps.

Attach the break lights, preferably different colors on buddy teams.

Make sure everyone knows the signs.

Check compass courses.

Who has the emergency facilities (and the car keys).