Whales are large and intelligent aquatic mammals. Usually found in the open ocean, they use intricate and mysterious sounds to communicate with other whales. Along with manatees, whales have the distinction of being the only mammals to spend their entire life in the ocean. Whales have a thick layer of fat called blubber, which protects them from the cold temperatures of the ocean water. All whales feature fins that are modified forelimbs, horizontal flukes on tails, with the top of the head featuring nasal openings. These majestic creatures are truly a sight to behold for any diver, and fortunately, inhabit all the world’s oceans and can be sighted at a number of popular diving locations worldwide.
The Blue whale is one of the largest animals to have ever lived on Earth. These mammals grow in length to up to 100 feet long and weigh over 200 tons. They reach these mind-numbing proportions on a diet consisting almost completely of krill, which are animals bearing a close resemblance to shrimp. The blue whale is a baleen whale, which means it has a fringed plate made of material resembling fingernails attached to its upper jaw for feeding purposes. The blue whale’s head is broad and flat and it has a long and tapered body, ending in wide and triangular flukes.
The Blue whale is one the loudest animals on the planet and emits a string of pulses, groans and moans to communicate. Blue whales can hear each other up to sixteen hundred kilometres away and its vocalisations are believed to be used for sonar navigation along with communication. Despite its enormous size, the blue whale is extremely difficult to spot, as it spends most of its life in the open ocean, though it can be sighted at a few dive spots like La Paz in Mexico, the Trinco coast off Sri Lanka and Baja California in Mexico.
Humpback whales are well known for their mystical songs, which can be heard hundreds of kilometres from the whale’s location. Humpback whales are easily recognised by their stocky body with a pronounced hump and a black dorsal colouring. They have abnormally long pectoral fins and a knobby head. The humpback is an acrobatic animal famous for breaching and slapping the water with its tail and pectorals. They are usually found near coastlines and feed on tiny shrimp, krill, plankton and other small fish.
These whales grow to an average length of fifteen metres and weigh roughly forty tons. They migrate annually to warm feeding grounds at the equator where they reproduce, leaving the cold feeding grounds of the poles. The humpback whale can be spotted at diving locations such as the Boa Vista in Cape Verde, Byron Bay, Port Douglas and Cairns in Australia, Bimini and Berry Islands in the Bahamas and Taveuni in Fiji.
The Minke whale is one of the most common baleen whales. Their flippers have a white band, which is an identifying characteristic of this whale and contrasts with its dark gray top colour. Minke whales generally grow up to seven metres long and have a life span of around twenty years. Breathing in short intervals for three to five times and then deep diving for twenty minutes, the Minke whale’s dive is preceded by a pronounced arching of its back. These whales can swim at a maximum speed of 38 kilometres per hour and are widely distributed throughout the world - commonly found from the poles to the tropics with a preference for the open sea.
The Minke whale is relatively abundant, which makes it the centre of attraction of whale-watching cruises setting sail from Scotland’s Isle of Mull, Ireland’s County Cork and Husavik in Iceland. These whales can also be spotted at well known dive sites at Tutukaka in New Zealand, Cairns and Port Douglas in Australia and Koh Lipe in Thailand.
The Sperm whale is easily identified by its enormous head and bulging rounded forehead. It has the largest brain of any creature to have roamed the earth and derives its name from a waxy substance called spermaceti in its forehead cavity. The function of spermaceti is still not known, but it is believed to help the whale regulate buoyancy. Sperm whales can consume thousands of squid and fish every day.
Sperm whales are usually found in gatherings (called pods) of fifteen to twenty whales, though male sperm whales usually roam solitarily, leaving the females and the babies all year long in the tropical or sub-tropical waters, where the females engage in cooperative childcare to ensure the survival of their young. The Sperm whale is a common sight at diving spots in the Bahamas, such as Eleuthera, Bimini, Nassau, San Salvador and the Andros.
Grey whales were at one time referred to as devilfish due to their aggressiveness when hunted. The Grey whale is frequently covered with parasites and other organisms, which make its snout and back appear not unlike crumbly ocean rock. The whale feeds by dislodging small creatures from the ocean floor with its snout. It is a renowned migratory mammal and travels more than twenty thousand kilometres from Alaska in the summer to the Mexican coast in the winter, and back. It grows to an average length of twelve to fifteen metres and weighs forty tons. The Grey whale, however, is reclusive in nature and is rather difficult to spot, though sightings have been confirmed at La Paz in Mexico.
The Narwhal is a moderately-sized whale found in the Arctic region all year round. The Narwhal has two teeth, with the protruding tooth in the males growing into a sword-like helical tusk up to nine feet long. Females too grow a little ivory tusk, though it does not become as large as the male’s. The exact purpose of the ivory tusk is not known, though it is speculated to be of importance in mating rituals, to either impress the female or to fight off rivals.
The Narwhal is usually found in the company of fifteen to twenty other narwhals, though reports of several thousand swimming together have also been made. These whales are found only in the Arctic region near and around Scandinavia, at places like the Baffin Bay, Davis Strait and Lancaster Sound, all near the coastline of Greenland.