Scuba diving is a sport that had its humble beginnings in ancient times. In early Greece and Rome, people use to swim or dive while holding their breath or by using makeshift breathing apparatuses like hollow plant stems. This was commonly practiced during combat or while gathering food and materials from the ocean.

One of the first stories of underwater breathing dates back all the way to 500BC, when a Greek solider supposedly dived off a ship and used a hollow reed to breath underwater for hours.

A couple centuries later, the philosopher Aristotle reported that Alexander the Great found a way to hide underwater while the siege of Tyre was taking place. Apparently, Alexander the Great was able to stay underwater by using a barrel as his very own diving bell!

We have come a long way since then. Underwater diving evolved from simple freediving or skin diving to the more sophisticated form that we know today thanks to contributions from many great minds throughout the centuries. Modern scuba diving is built on thousands of years’ worth of innovations in underwater technology, not to mention all of the physiological research on the effects of underwater pressure on the human body and the efforts to create standardized training programs for amateur divers.

For the first nine months of our lives, we humans exist in an aquatic environment very similar to seawater. If an infant is submerged underwater, it instinctively holds its breath for up to 40 seconds while making swimming motions, although we seem to lose this ability as we get older and commence walking. Awakening these reflexes is one of the most important elements of freediving, thus giving humans better abilities to survive at great depths.

The history of scuba diving is closely linked with the history of scuba equipment. By the turn of the twentieth century, two basic architectures for underwater breathing apparatus had been pioneered; open-circuit surface supplied equipment where the diver's exhaled gas is vented directly into the water and closed-circuit breathing apparatus where the diver's carbon dioxide is filtered from the exhaled breathing gas, which is then recirculated, and more gas added to replenish the oxygen content. Closed circuit equipment was more easily adapted to scuba in the absence of reliable, portable and economical high pressure gas storage vessels.

By the mid-twentieth century, high pressure cylinders were available and two systems for scuba had emerged: open-circuit scuba, where the diver's exhaled breath is vented directly into the water and closed-circuit scuba, where the carbon dioxide is removed from the diver's exhaled breath which has oxygen added and is recirculated. These are called rebreathers.

In 1942, during the German occupation of France, Jacques-Yves Cousteau and Émile Gagnan designed the first successful and safe open-circuit scuba, known as the Aqua-Lung. Their system combined an improved demand regulator with high-pressure air tanks. This was patented in 1945.

MALDIVES ON A LIVEABOARD

What is Channel Diving?

Channels are usually formed as gaps or breaks in the atoll, forming entrances and exits to the inside eco system. Diving in them is best with a medium strong incoming current from the East. The current strongly affects the quality and nature of the dive. Often with a strong outgoing current there is less fish life and the dive becomes more challenging.

The beauty of channel diving is the amount of fish life in general, but particularly the fact that pelagic life rides the current, waiting to hunt smaller fish that slip from their schools. The mix of pelagic life and reef life creates an interesting mix of sights and behaviours.

Crossing the channel

A small to medium incoming current is ideal for crossing the channel; the oceanic current pushes you along the outside drop off from one corner to the next. It is important to be further away from the reef and below the lip of the channel floor to avoid being swept into the channel. Often this means that you have to be at 35-40 meters deep - staying shallower would mean not being able to cross the channel. If the current is not too strong, you will see a lot of marine life hanging on the edge of the channel. They do this because they breathe the water being pushed through their gills, and with the current passing through them, they don’t have to swim.

Hooking on to one of the corners

This is usually done when the current is medium to strong. Drift along the outside wall until you reach one of the corners, hook in with a reef hook, and observe the marine life activity around you.

In the Maldives, it can be really challenging to cross the channel in a strong current. Often the channel changes direction as you cross, and by the time you reach the opposite lip of the channel, the current starts working against you if done with an incoming current. It is possible to run into a washing machine style scenario that will have you kicking hard to get out. It is best to stay close to your dive guide and mimic him or her very closely.

Sharks and eagle rays are often gliding on the current at this point, as well as hunting and feeding on fusiliers. You get to observe all the action from the corners.

Things to be careful about

The converging currents can create washing machines of a sudden mix of upward and downward current. Often it is necessary to swim through this type of current for a stretch to get to the other side of the channel. To negate this, release your SMB and become negatively buoyed - essentially hanging off the SMB.

On channel dives, it is critical to bring SMBs, reef hooks, and ideally a nautilus life line or similar product, as there is a fair chance of being swept out into the blue.

MANTA RAYS

Any diver, however experienced he might be, is always surprised and moved by a night dive surrounded by manta rays. This dive, 8-meter deep in a lagoon, shows the learning abilities of these animals, the fish with the biggest brains. A powerful spotlight is located on the stern, attracting great amounts of plankton. Manta rays feed precisely on plankton and they respond in an extraordinary way to any animal’s most important instinct: feeding.

Given the big amounts of food that animals as big as manta rays need, their behavior is strongly marked by their food needs: when finding a great concentration of plankton, manta rays focus all their attention in eating as much as they can, ignoring virtually everything else around them, even the divers. Manta rays pay so little attention to us that we can even feel their graze: all we have to do is open our eyes and enjoy a magical experience that can move the diver to tears.

As the largest fish in the sea, reaching lengths of 12m (40 feet) or more, whale sharks have an enormous menu from which to choose. Fortunately for most sea dwellers and us, their favorite meal is plankton. They scoop these tiny plants and animals up, along with any small fish that happen to be around, with their colossal gaping mouths while swimming close to the water's surface.

Filter Feeding

The whale shark, like the world's second largest fish, the basking shark, is a filter feeder. In order to eat, the beast juts out its formidably sized jaws and passively filters everything in its path. The mechanism is theorized to be a technique called “cross-flow filtration,” similar to some bony fish and baleen whales.

Characteristics

The whale shark's flattened head sports a blunt snout above its mouth with short barbels protruding from its nostrils. Its back and sides are gray to brown with white spots among pale vertical and horizontal stripes, and its belly is white. Its two dorsal fins are set rearward on its body, which ends in a large dual lobbed caudal fin or tail.

Population

Preferring warm waters, whale sharks populate all tropical seas. They are known to migrate every spring to the continental shelf of the central west coast of Australia. The coral spawning of the area's Ningaloo Reef provides the whale shark with an abundant supply of plankton. Although massive, whale sharks are docile fish and sometimes allow swimmers to hitch a ride. They are currently listed as a vulnerable species; however, they continue to be hunted in parts of Asia, such as the Philippines.

According to the IUCN, the Indo-Pacific population of the whale shark is thought to have reduced 63 percent over the past 75 years. The population in the Atlantic is thought to have been reduced more than 30 percent. The populations are continuing to decrease. Because of this, whale sharks are classified as endangered.

Moalboal is famous for its large turtles that frequent the waters. In fact, there are so many that you will struggle to not find a turtle while snorkeling or diving in Moalboal. If for some reason you have not, try to stick to the shallower waters closer to shore, just before the drop-off wall of the reef. After a short while you will no doubt spot one of these beautiful animals eating fresh sea grass.

Moalboal is a must visit for any diver coming to the Philippines. The main attraction is the famous sardine run but I was amazed by the large number of turtles. I have never encountered so many on a single dive.

This part of the globe has six of the seven species of turtle that exist. In Moalboal we mainly see two of them, the Green turtle and the Hawksbill turtle. In many parts of the world if you were to see one or two turtles on a dive you would be buzzing about it all day, here you can loose count of how many you see, sometimes twenty plus per dive.

MOALBOAL'S SARDINE RUN

Over a decade ago, Cebu’s sardine run was reportedly non-existent, and their sudden appearance at Panagsama Beach is a mystery. Regardless, the Moalboal community have welcomed the effect their fishy friends have had in the area. No mass fishing is permitted, but local fishermen can use small wooden boats to fish with just a hook and line and the sardines have encouraged more people to visit the area each year.

The annual sardine migration along the east coast of South Africa might be more recognised, but coming to Moalboal is notably different. Development and tourism remains relatively slow, so during my visit in June 2017, I was one of a handful of people diving the reef.

Sardines are not your typical tropical fish. But, envisage luminescent, ethereal figures swirling beside you, against a deep blue backdrop. For the entire hour I was scuba diving with them, the fish looped in mesmerising undulating formations. The shoals of sardines move through the ocean like flocks of starlings, often creating spherical shapes known as bait balls in order to trick their predators. Conveniently for spectators like me, these small fish rise close to the ocean’s surface to stay warm and to feed on plankton.

Whether you are a capable deep-sea scuba diving, a budding freediver or a mellow snorkelling enthusiast, the sardine run is suited to all aquatic abilities. Much of Moalboal’s appeal to ocean explorers is the reef’s ease and accessibility. The tide is usually calm with a lack of current, and the weather conditions are steady in the right season (November to April).

If snorkelling is your preferred method, you are in luck. You don’t need a boat, because of the proximity of the reef to the shore and the sardines swimming close to the surface, you can simply wade out. If you have your own equipment, it is totally free! Alternatively, hire a mask and snorkel from a beach bar or shop, there are plenty to choose from.

There are benefits to scuba diving the reef, however. It is soothing drifting along the current and getting closer to the shoals and visibility is more guaranteed. Diving gave me a chance to navigate and explore 15m of the 70m-deep reef’s plunge, as there is plenty more than sardines to see.

GREAT WHITE SHARKS