The following article ‘Night Diving: Dos and Don’ts’ originally featured in issue of Asian Diver (volume 115, 4/2011) which includes some tips for happy night diving. In the same issue I has an image in the ‘Art of Diving’ section of a basket star shrimp (Periclimenes lanipes) running around its echinoderm host, taken at Wakatobi Dive Resort in Indonesia.
NIGHT DIVING – DOS AND DON’TS – By Richard Smith (2012)
As the sun sets an entirely different mood shrouds the reef. Without the daytime bustle and colour to steal your attention the cacophony of noise is striking and immediate. The last few fusileers dash to find a hollow for the night as the first echinoderms and crustaceans emerge from their haunts. It seems relatively few intrepid divers actually enjoy night diving, but with a little thought and planning it is an exciting and rewarding time to dive.
Night diving can either be one of the best or worst underwater experiences. Sometimes, I’ll admit, the prospect of getting back in the water at night when your core body temperature is low after a day of diving isn’t all that appealing, but having made the effort you’ll rarely regret it. For even veteran divers however, bad experiences on one or two occasions put them off the idea altogether. I would strongly recommend giving it a second chance, taking some tips on making the most out of your night dives into consideration.
Whilst your torch is charging, the best preparation for your impending night dive is to go diving! Visiting the night dive site during the day is one of the best ways of preparing yourself for what’s to come. Experiencing the topography and layout of the reef will really help you to prepare you and you’ll be much more relaxed. People who are anxious about night dives will have some of these worries quelled by a knowledge of the topography. When you’re more relaxed, buoyancy will come more easily and reduce contact with the reef, which both unnerves the diver and damages the reef’s delicate creatures.
Don’t: Dis the Dusk
Guides will often try and have their divers in the water when it still seems relatively bright on the surface. This makes a lot of sense as, whilst it’ll be much darker underwater, the dwindling light helps immensely with orientation, plus it’s easier to prepare equipment. Dusk is also one of the best times for observing behaviours such as fighting, courting, mating and spawning. Like night diving, it is best to take your time and spend a while observing the reefs inhabitants at a slow pace as light levels fall. Those fish that seem unusually close or active might just reward you with a little show.
Do: Go it Alone
Good guides or instructors are vital for the enjoyment of night dives but personally I enjoy night dives much more when my buddy and I stray a little farther a field from the group. Novice and experienced divers alike have a tendency to cling very closely to the guide, reducing the enjoyment of all. Obviously you may want to stay close enough to your guide for them to point out interesting animals, but much of the enjoyment in night diving is gained from the feeling of solitude, tranquillity and finding things for yourself. Reports of bad dives usually come from people caught up in a scrum of divers clambering around the guide.
Don’t: Use too Bright lights
A good torch or flashlight is obviously the most important piece of equipment in a night diver’s arsenal. By good, I consider reliability to be the most important feature of a torch. People often mistakenly think that a torch as bright as the sun will be most appropriate but this makes watching nocturnal animals next to impossible. The beam of a bright torch will send even eyeless nocturnal reef creatures such as basket stars scampering for shelter. I’ve found that more subdued torches are most useful for observing behaviours especially when the outer rather than main beam is used to highlight the subject.
Do: Carry a Spare and a Strobe
Torchlight is also the night diver’s tool for communication so it’s important to have a spare one on you at all times as a backup might be your only way of attracting attention under or above the water should your primary fail. Another light that can be useful is a small flashing strobe attached to the tank. Battery powered versions are preferable to glow sticks as the latter can leak and the chemicals within them are toxic. These flashing strobes allow buddy teams to keep track of each other in groups of other night divers.
Don’t: Harass daytime creatures
As a rule of thumb animals that are active during the day should be avoided as subjects at night. They might be easier to observe and photograph but waking them from sleep severely disturbs them. Imagine yourself in their shoes, woken from sleep by a huge spotlight. The bright lights disorientate them, making them easy pickings for predators. Ghost pipefish for example can’t see a thing at night and bump off the reef by their snout when blinded by a torch beam. Similarly, pygmy seahorses are equally harassed if observed by divers at night.
Night diving allows you to see the reef in a whole new light, so to speak. Taking a slow approach will reward you with sightings of new and fascinating creatures as they emerge from their daytime retreats. Treat your role in the lives of these creatures as an unintrusive bystander rather than a night terror and you’ll want to brave the inky black waters as often as you can.
An unusual phenomenon on the reef is the appearance of various red creatures as the sunsets. Think of the night octopus, Spanish Dancer nudibranch or soldierfish; they’re all bright red! Despite seeming ridiculously conspicuous to us, this is in fact a form of camouflage. You may remember from your Open Water course that red is the first colour in the visible spectrum to be absorbed by the water. As a result, few marine creatures bother to include the colour in their visual repertoire and red animals are practically invisible to predators. For night divers, a different way of viewing nocturnal creatures and their behaviours is to use a red filter over the torch to create a less harsh light to observe the animals.