Whale Sharks Season Similan Islands Thailand

Whale shark similan islands Ask any diver what is on their bucket list of things to see underwater, and in all likelihood the majestic whale shark will be top choice for almost every diver. This beautiful and utterly enormous creature attracts divers like the proverbial moth to a flame for several reasons. Firstly, they are fantastically huge and are the biggest fish you will ever see underwater. Secondly, the mighty whale shark is completely docile and non-threatening. Finally, due to its nature and nonchalant attitude towards divers, it is possible to get very close to this beautiful creature.

Whale Sharks Season in Thailand

When is the Whales shark seaon on the Andaman coast of Thailand?

Here at the Similan islands, the best way to see a whale shark is to go on the liveaboard as the more dive you do the more chance you will have to see it!!

The season start around January depending on the year and ends end of Mai, around this time of the year the plankton is increasing with some plankton loaded currents, the whale shark feeds on plankton that s why they come around this time of year with the Manta Rays as well!!!

Richelieu Rock is the Whale Sharks Diving Spot, Whale Sharks at Richelieu Rock is one of the main attraction of the dive site with as most of the pinnacle around the Similan islands offer more chance to see them.

Koh Bon Pinnacle, Elephant Head Rock at the Similan islands, Koh Tachai Pinnacle are some of the best dives spot around to see the giants and offer you great diving with a change to spot the whale shark!!!

Join our Similan liveaboards and meet the Whales sharks!!!

Fond some more info about whales sharks at: http://en.wikipedia.org/wiki/Whale_shark

Whale sharks around the World

Habitat and distribution

whale shark repartition The whale shark (Rhincodon typus) is pelagic and lives in all tropical and warm temperate seas; as a pelagic species, it spends most of its time in the open ocean. The range of the whale shark is enormous and stretches from Australia to the Caribbean and from southern Africa to the Indian subcontinent. In fact, it is often found in waters that have a temperature above 22 degrees Celsius, and is rarely encountered in waters below that temperature.

Biology and feeding

whale shark feeding The whale shark, unlike most other sharks, is actually a filter feeder; in fact, it is one of only 3 types of sharks that filter feed – along with the Basking shark and the mega mouth shark. Although the whale shark’s mouth has 300 to 350 rows of tiny teeth, these play no role in feeding. The shark feeds, using 10 filter pads, primarily on plankton, including fish eggs, krill, copepods, and small fish and squids. To be able to process the tons of nutrient rich water, it uses one of two feeding methods.
Firstly, the shark can use ram filtration, in which it opens its mouth and swims forward, driving the water into its mouth. The second method used by whale sharks, possibly to eat more localised food sources, is through suction feeding. In this method, the shark opens and closes its mouth, creating a pressure differential and sucking in enormous volumes of water and nutrients.
As the water flows into the mouth of the whale shark and out through its gills, it passes parallel to filter pads which then catch most of the smaller food particles, while the heavier larger particles are driven to the back of the throat. The shark then consumes the food trapped in its filter plates. Over time, it is theorised that these plates become blocked with unconsumed nutrients – to clear this blocking, whale sharks have been observed to cough to “clear their throats”.

Whale shark sex and birth

Sex of whale shark Whale shark’s mating and overall reproduction habits are shrouded in mystery. No mating or births have ever been observed and the whole process is relatively unknown. What is known from captured specimens is that whale sharks are ovoviviparous, and the eggs develop inside the female until live young are born. Interestingly, the female does not lay a clutch of eggs which develop into live young, but will actually retain sperm from the mating and over a prolonged period of time, will produce a steady stream of pups.
Very little is known about the development of juvenile whale sharks, since they are hardly seen anywhere. And despite the fact that the majority of time we seem to only start noticing whale sharks when they hit 3 metres’ length, what happens to them before that is a kind of mystery. The smallest whale shark ever recorded was a specimen measuring 38 cm, which was found in the Philippines in 2009 on a beach with its tail tied to a stake.
The method to identify whale shark sex is similar to the the one for sharks.


Male Shark
male shark sex determination

Female Shark
female shark sex determination

You can find plenty of information about whale sharks and sharks in general with our colleagues at:
Marine Megafauna
Shark Guardian

Threats by Humans

whale shark threats Chinese restaurantwhale shark threats by humans

Like most sharks, the whale shark is subject to pressures from humans and other environmental factors. They are threatened by pollution, boat collisions, plastic and floating debris and deliberate fishing. Due to so many unknowns surrounding total numbers, breeding cycles, and population health, whale sharks are sadly classed as vulnerable by the IUCN Red List.

Where are the best places to see whale sharks?
There are many places around the world that are known for whale shark sightings, and sharks have been seen from Thailand, Australia to Israel and south Africa to Pakistan. However, some areas seem to have a much bigger population and a much higher frequency of sightings. The places to go with the best chance of an encounter are Thailand, especially at the Similans and Richelieu rock, the Ningaloo reef in Australia, the Maldives and Utila in Honduras. One thing to note is that in almost all the places where whale sharks are encountered, they are not perennial, they appear for a season then they are gone; it is always best to check when the whale shark season is where you choose to go.
Is there any particular whale shark diving etiquette?
Although whale sharks may seem impervious to divers, and seem to just go about their business, we do have an impact on them and as such care must be taken when interacting with them. This first and obvious rule is not to touch them or hang on them – they are not in the water for your personal amusement. Secondly, do not obstruct their path so as not to force them to change their route. Finally, stay relatively clear of the head and mouth of the shark, especially one that is feeding.

Whale shark code of conduct

How big do whale sharks actually get?
Well, this is somewhat of a tricky one. Officially, the largest whale shark ever caught and examined was captured in 1947 near Karachi, Pakistan. This enormous specimen came in at 12.65 metres and weighed a whopping 21.5 tons. However, as with most things whale sharks, the mystery deepens since this is probably neither the biggest nor the heaviest whale shark there is. Over the years, there has been many reported sightings and reports from reliable sources that indicate lengths up to 18 metres regularly and even in some cases up to 21 metres. Weight estimates have also been in the range of up to 45 tons. While these supersize specimens probably exist, scientists estimate that the average adult size of a whale shark is 9.7 metres with an average weight of 9 tons.


Are there any whale sharks held in captivity?
Sadly, yes there are. Over the years, whale sharks have been held in aquariums in the USA, China, Taiwan, and Dubai. Whatever you feel about seeing such majestic creatures in the confined space of a tank, this diver is sure of one thing. Fish of that size and magnitude belong in one place only: the Sea. As a diver, encountering a whale shark in its natural environment is worth much, much more than any number in a confined space.