Night diving is one of the most spectacular types of diving you can do. Some of my best dive experiences have come from diving at night.
Training for a night dive is included in part of the Advanced Openwater Diver course or Night Dive Specialty course. However, generally, any diver with more than 25 dives can give it a try. The main attraction with night diving is the amazing marine life you will encounter especially if you are diving on a coral reef. For your first time on a night dive, the experience can initially be a little dis-orientating as normal points of reference in the dark are not available, so use of descent line and a close eye on the depth gauge is important
All the critters and animals come out to forage, explore and socialise at night. It’s almost like party time! Many creatures hidden by day are on full display at night especially. Bright pink and blue lobsters, multi-coloured free swimming eels, giant fiery orange/red crabs, coral-banded shrimp, colour-changing chameleon octopi march across the reef. Parrot fish and other fish can often be found sleeping in a nook in the reef while others are attracted to the light and give you a close inspection and of course curious sharks appear out the darkness. I’ve come across creatures that I’ve never seen before. I recall one animal on a dive in St Lucia, which was essentially a giant 2m long , as thick as my forearm, centipede like creature bright orange in colour and sensitive to light. It lived in deep hole under an underwater archway. To this day I still have no idea what it is. I never saw it by day, only at night.
Coral feeding – If you pay close attention to the coral heads, you will see their colony of polyps protruding and reaching out for voracious feeding, something you do not see by day. A cool trick is to shine your light close to a coral head; smaller creatures like sea lice, wee shrimp and bug-like animals, which are attracted to the light will arrive, and if they come close to the coral polyps, they are easily trapped by the polyps and slowly eaten.
With your dive light and providing light right on the reef and marine life itself, you will have a maximum colour effect with a kaleidoscope of rainbow spanning colours. A combination of the intense colours and tons of marine life is a very impressive underwater spectacle.
Diving by moonlight, full moon vs. new moon. A full moon means a lot more reef activity and it can be so bright that you can often spend part of the dive diving by just the moonlight alone with your light off for a short period. Diving by a new moon or no moon, really is pitch black and re-enforces the colour effect from your light.
There are a number of safety precautions and techniques used for night diving:
Perfect conditions is the norm with minimal sea chop and current. Depth should be limited to the shallows, no deeper than 18m. Dive groups limited in size to maximum 4 people per instructor/guide. Entries into caves, wrecks, drifting with currents and diving on a deep wall should be avoided. Each diver should have one main light and another as back up and dive lights should be stored with the batteries removed when not in use. I’ve seen plenty of light failures underwater and so the back-up light is essential. The dive boat should hang a strobe light underneath to assist with uw navigation and orientation. Glow sticks should be used to all divers especially if group dives are conducted, each group with a specific colour glow stick. They can be zip-tied to the first stage of your regulator next to the tank valve. Back up glow sticks and strobe lights are also strongly advised. Navigation from the shore or boat should be restricted to a smaller area near the entry and exit points to avoid getting lost.
Communicating and Signalling underwater:
There are a series of special signals for using your lights to communicate or you can shine your light on your hand to light up your hand signal. Do not shine your light into someone else’s eyes or face to signal to them; this will cause a temporary blindness which can be very disorientating. Dive instruments have fluorescent glow in the dark material displays when charged with a light, like dive watches, so you can see your depth and pressure gauges clearly.
No time like now to give night diving a go, I guarantee you, you won’t be disappointed.
Big Bubbles, No Troubles!