Drift diving

Drift diving is a popular form of diving which is defined not by equipment or technique, but by location and water currents. In most open water diving situations the scuba diver propels himself by swimming and kicking the fins. In drift diving the diver descends into water with a known current and after obtaining neutral buoyancy lets the current just carry him along.

Drift diving is arguably the most relaxing and pleasant diving experience there is. Because the diver is not exerting himself by swimming, he uses less air and thus can stay submerged longer on a single tank. Many popular drift diving reefs have currents which run parallel to the reef; once submerged the diver relaxes and watches the scenery float by; using only minimal effort to stay neutral and navigate around formations.

The whole point of drift diving is to "go with the flow" and not to swim against the current. The movement is often so gentle that divers don't realize how powerful the current is; but they may soon realize its force when trying to swim against it! With a group of divers swimming into the current differences in swimming strength and fitness quickly become apparent since some divers swim easily upstream while others struggle to keep up. Going with the current a large group of divers can stay together very easily. Regardless of fitness level or swimming strength swimming against a strong current will use more air and the exertion of fighting the current shortens the diving experience.

Drift diving is almost always done from a boat drop-off, you must have someone on board to follow you. Once you begin drifting you will be carried quickly away from your drop-off point - often much more quickly than you realize or expect. It is very important for the boat captain to know which way the current is flowing and follow you from above. In calmer water (especially with larger groups of divers) the boat captain can see your bubbles and follow them. It is a very good idea for your group to have a surface marker buoy, on a reel, that you can send up when you begin to ascend - the boat will see it and approach to pick you up.

Bali water have many drift diving sites, especially on the Nusa Penida side of the island; Ped, S.D, Sental, Toyapaka, to name just a few. Enjoy your diving.

Nudibranch facts

We've all seen these colourful little critters whilst diving, but how many of us actually know some facts about them:

What is a nudibranch or sea slug? Although the term “slugs” conjures up all kinds of unpleasant ideas, nudibranchs (pronounced “noo-dee-branks”), more commonly known as sea slugs, are renowned for their boundless variety and beauty. Nudibranchs are gastropod molluscs.

What do they look like? Nudibranchs are shell-less molluscs, so imagine a colourful snail without a shell. Different species have a vast variety of body shapes and range from a few millimetres to 30 centimetres long. The word nudibranch is Latin and literally means “naked gills”. The name refers to the circle of exposed gills on the back of many species.

Where do they live? Nudibranchs can easily be seen by observant divers in all of Bali's dive sites. On reef walls or reef tops, they may nestle among an array of other invertebrates, such as sponges, on which some predate. However, hundreds of species of nudibranchs that have so far been recorded in Bali waters. Divers willing to investigate nooks and crannies can often spot species that have not yet been scientifically described.

What they eat and how: Nudibranchs are exclusively carnivorous, and, depending on the family and the species, often feed on a specific species of prey. Some species, for instance, feed exclusively on mollusc eggs, others on a particular species of sponge.

Behaviour: With no shells for protection, nudibranchs have had to develop a vast armoury of alternative defences. Some species can produce a distasteful noxious secretion to deter potential predators, such as fish. Other species feed on sea anemones, hydroids, jellyfish, soft corals and hard corals and are able to store special stinging cells called nematocysts from these animals food they eat. When attacked, they can discharge the stinging cells to deter their predators. Other nudibranchs use camouflage to avoid detection. Most nudibranchs have intricate and vivid colour patterns to advertise to predators that they are dangerous to eat.

Breeding: All nudibranchs are hermaphroditic, that is, the animal acts as both a female and a male. Copulating pairs inject sperm into each other by a penis. Eggs are usually deposited by each individual in a coiled mass on underwater surfaces. A few species emerge from the egg as a crawling juvenile. However, most emerge as free swimming larvae, with a tiny remnant shell. These swim about in the water column until they are ready to settle on the bottom.

How you can protect nudibranchs: When diving or snorkelling, look at but don’t touch these soft-bodied animals.