Dive at night?
Why?
If you’re new to diving and have never tried it, the idea might seem strange, or even intimidating. What can you see at night that you wouldn’t during the day?
Think about a nocturnal stroll through a familiar park. At first it seems a little scary perhaps, but as your eyes adjust to the dark you relax, recognizing the familiar paths and trees. It’s the same place that you have seen many times during the day, yet somehow different.
Your flashlight illuminates a jasmine blossom that opened at nightfall; you almost didn’t recognize it as the same flower that you see during the day. The birds that normally flit about are gone, but a different bird – one you’re not familiar with – whistles in the darkness. It’s the same park, but already you have discovered something new and fascinating about it.
Visiting a favourite, familiar dive site at night can be like visiting a whole new dive site. You may feel a little bit anxious about going underwater in the dark – no worries, that’s natural and foe some, even a bit of the fun. But, as you explore applying the techniques you’ll learn in this section, you’ll find curiosity and excitement replacing hesitation and anxiety. Chances are, before the dive ends you’ll be fascinated with night diving, already ready for your next.
The appeal of night diving and night diving activities:
Why dive at night?
Just as different people dive for different reasons, they have different reasons for night diving. Probably you can find as many reasons for diving at night as there are night divers, but you’ll find these five reasons again and again.
Natural curiosity: “Because it is there,” justifies night diving just as well as it justifies mountain climbing. You may want to night dive simply for the excitement- to do something you’re curious about because it’s a bit different and a bit more adventurous then daytime diving. Know what? That’s all the reason you need. To observe aquatic organisms: At dusk, nocturnal animals such as lobsters in salt water or catfish in fresh become active. Animals that are difficult to approach by day, including many fish, let you get closer at night. Still others that you’re quite familiar with look very different at night.
Coral polyps open at night to feed, for example, making the reef look “fuzzy” and colourful instead of hard and rocky.
A new look at old sites: The same “old sites” takes on new appeal at night.
It puts a spark back into visiting dive sites that have lost some of their daytime fascination.
Night diving gives you a reason to revisit familiar dive sites, because in the dark, they’re not quite so familiar any more.
More chances to dive: You may discover that night diving equates with diving more.
While your work schedule may make day diving impossible most days, you may have adequate time to get wet after work.
Colourful dives: As you recall from your entry-level course, water absorbs colour so that you deeper you dive, the less colourful the scenery.
When night diving, however, you take your light with you, and the beam doesn’t get filtered through very much water.
This means that at night, the colours appear more vibrant and “true” than during the day.
Things to do at night: Swimming around exploring at night is interesting, but you’ll find that darkness enhances, or adds a new twist to different diving activities, notably, sightseeing, underwater photography, and wreck diving benefit from night diving.
As mentioned, you’ll see aquatic life at night that you seldom see during the day, and you’ll observe behaviours and phenomena unique to the after-sunset environment.
In the ocean, for example, you may encounter bioluminescence – chemical light flashes microscopic plankton generates when a diver disturbs them.
When bioluminescence is present, cover the light and wave your hand through the water.
As you do this, you’ll see “sparks” ignite in its wake.
If you’re into underwater photography, you’ll find that night provides a dramatic black backdrop for striking pictures, plus opportunities to photograph nocturnal creatures and behaviours.
In fact, you might find that you prefer night photography to day photography.
Of all the sites that take on new character after dark, it’s hard to beat a wreck.
At night, wreck diving can be a mysterious experience, with the ship taking on a new dramatic dimension.
If you are interested in wreck diving, the wreck adventure Dive and the wreck specialty course offer guide introductions to visiting sunken ships.
Among other things, you learn on a night dive, you don’t enter a shipwreck because there’s no natural light to help you find your way out if you become disorientated.
Entering a shipwreck (or any other overhead environment, for that matter) requires special training, equipment and techniques; to do so without the proper equipment and training places you in unnecessary and excessive risk.
Night Diving Equipment.
Ask almost any diver what special equipment you need to night dive, and you’ll get the answer.
“A dive light or torch”. Okay that’s pretty obvious, and we’ll focus entirely on dive lights in a moment.
But night diving has some other equipment considerations, which we will cover here - everything other than lights.
Aside from lights, your personal equipment for night diving does not differ much from day diving,
but there are a few points worth attention.
It’s always recommended that your alternate air source is be clearly identifiable and secured in the triangle
formed by your chin and the lower corners of your rib cage, where you or your buddy can find it easily.
For diving at night, if your air source isn’t conspicuously coloured already,
you might consider adding a bright coloured hose protector to make it stand out better in the dark.
Since you will have light in one hand, you’ll want one-hand BCD control – which is probably how it already set.
You should have complete instrumentation – depth gauge, timer (or dive computer) and compass –
ideally with luminous/illuminated markings for easy reading. A reference line from a boat or a buoy will make your descents/ascents easier,
and for reliable communication, take your slate. For surface communication it is a good idea to carry
an audible signaling device like a whistle or air horn (device that attaches to the low-pressure inflator of your BCD),
especially at night so that you can make your presence known in the dark if necessary. Attach the whistle to your BCD inflator hose near the mouth piece,
where it is out of the way but ready for immediate use, and attach the air horn to your low-pressure inflator.
Depending n the environment, it’s often wise to protect yourself with an exposure suit, booties and gloves.
It’s a bit easier to bump into things in the dark, which can cause some scrapes or cuts if you’re unprotected.
Remember though just because you are protected from the reef doesn’t mean the reef is protected from you.
Take extra care at night to avoid blundering into fragile corals or other aquatic life.
It’s generally recommended that you avoid using new or unfamiliar equipment at night. You want to work with familiar,
comfortable equipment on a night dive ( or any other specialized diving activity, for that matter).
If you have acquired a new BCD, regulator or other equipment, it’s best to become familiar with it during the day under
favorable conditions before diving with it at night.
Night diving lights:
Obviously you need a dive light, or torch as some call it, at night not just to see the reef,
but to read your gauges and to show your buddy where you are. When you not near an ascent line,
without a light it can be tough to make a slow, controlled ascent.
Although you’ll find modern dive lights tough, reliable and trustworthy, even the best of them fail.
That’s why you really want to dive with two dive lights – your primary and a backup.
Although it sounds a bit paranoid, some divers can carry three or four lights,
just to ensure that neither they nor a buddy won’t have to end a night dive without one.
Choosing a Dive light:
There are dozens of dive lights that you can choose from, so finding two you like shouldn’t be a problem.
Generally, you’ll by a big bright, wider beam light as your primary light, and a more compact light as your backup.
The primary light will be in your hand, and you clip your backup light to your welt belt or your BCD,
tuck it in your BCD pocket or carry it in some other way.
When selecting dive lights, look for these six features:
Rugged outer case:
Most dive lights are made from plastic or aluminum to resist corrosion.
Regardless of which, choose the most rugged, tough light in your price range.
This isn’t a license to abuse your lights, but they get banged up against other equipment, dropped on decks,
and slammed against the bottom despite your best efforts. Choose lights with this in mind.
Dependable switches:
The three most popular switches are indirect (magnetic or screw-down lenses), o-ring gland and rubber-boot covered switches.
With proper maintenance (discussed shortly) all are reliable. A lock mechanism (which isn’t possible with all switch types)
prevents accidentally running your batteries down while the lights in your bag, which you may find a nice feature.
O-ring seals:
The fewer o-ring sealed openings, the easier the maintenance and the fewer potential leaks.
This is one advantage of screw-down lens models.
Some lights have two o-rings and one opening for added reliability.
