If you want to swim among underwater aliens and take your night diving up a notch, why not try blackwater diving? This style of submersion - which involves suspending yourself in open water at night - allows you to witness the world's largest daily migration, called diel vertical migration. Every night, billions of tiny creatures move from the ocean's depths towards the surface in search of food. Armed with a torch and some sting-proof divewear, slip into the water once the sky is black to see bioluminescent beauties dance in the current. There are, of course, some extra safety considerations to bear in mind, but for those who are willing to dive into the darkness, there's a whole world of marine marvels waiting to be spotted.
Tempted? Read on to find out more about blackwater diving and why it should be added to your diving bucket list.
What is blackwater diving?
Blackwater diving is a night dive that happens in the open ocean, often far from reefs or rocky shores. Instead of exploring the seabed, divers are suspended in the water column, often over extremely deep water. Powerful lights are lowered from the boat to simulate moonlight, attracting deep-sea creatures to the surface. Not all blackwater dives are in open water; some occur near walls but with a stretch of open water on one side and a large depth below. After all, this type of diving is all about drawing the deep-sea creatures up.
During the dive, the boat drifts with the current, and divers are usually tethered to it via a rope clipped to their BCDs. This tethering helps prevent drifting away in the dark, open ocean. Divers descend to around 20m and either swim around the lights or remain close to the boat, depending on the operator's guidelines and local conditions.
Not all dive companies tether divers to the line; in some cases, you'll swim freely in the open water, staying close to the light source as a reference to where the boat is. However, this type of blackwater diving is more suitable for those who have done it several times, and it can be disorienting swimming in the open water in near pitch-black while trying to watch the tiny creatures, keep an eye on your depth and know where the boat is.
What can you see while blackwater diving?
Every night, the largest migration on Earth happens, as billions of deep-sea creatures ascend to the water's surface. This event is known as the diel vertical migration, drawing up tiny plankton to feed on the moon's light. It's not just the tiny plankton on the move - larger creatures like squid and krill make the journey, too. This migration is so massive it can be spotted from space.
Blackwater diving isn't about coming face to face with the giant sea creatures; it's about witnessing the billions of tiny animals - from fish larvae and juvenile fish to squid, salps, jellyfish and octopuses - that you'd never usually have the chance to see. These creatures may be small, but they are intricately formed and often translucent or bioluminescent, lighting up in the water when disturbed and creating a stunning display.
The sheer variety of rarely seen creatures makes blackwater diving a favourite for underwater photographers, looking to capture stunning neon images of cuttlefish, squid and jellyfish floating against a black backdrop. If you're lucky, the number of small creatures will, in turn, attract some larger boys like dolphins, manta rays and even sharks.
Do you need extra training for blackwater diving?
There isn't any specific blackwater diving certification but, it's highly recommended that divers have night-dive experience before attempting blackwater diving. Depending on the dive school that you go with, some may have suggestions of how many dives you've done previously and have a minimum of 50 completed dives under your weight belt.
When it comes to special skills, good buoyancy control is vital for blackwater diving. Diving in the near black over open water can be disorienting, so knowing how to maintain depth is very important to ensure that you don't dip too deep or bounce to the surface. Of course, this mainly applies to blackwater dives where you're swimming freely; if you're tethered to the line, you'll have a better idea of your depth.
Regarding extra kit, you'll carry two underwater torches, a primary and a secondary. Due to the number of deep-sea creatures, many of whom have defensive stinging abilities, it's a good idea to wear proper exposure suits, gloves and a dive hood. After all, getting stung by a jellyfish during the day isn't fun, let alone in open water in pitch black.
Where are the best places for blackwater diving?
Blackwater diving can be done in any open body of water, but of course, we have our favourites. Head to Anilao in the Philippines for pelagic seahorses and blanket octopus. Lembeh in Northern Sulawesi is already known as the muck diving mecca, famous for its wacky creatures by day. But when you add in some of the bizarre critters from the deep during blackwater dives, it feels truly extraterrestrial. For some blackwater diving with background music, head to Pico in the Azores, where the ocean drops off dramatically over 3,000m. You'll come across all kinds of bizarre, translucent creatures, to the backing noise of eerie clicks and clatters of sperm whales echoing through the deep.
