Giants of the deep

‘Papa Shilingi’ is what locals on Mafia Island call the whale sharks that breed nearby – ‘papa’ means shark and ‘shilingi’ is coins, because these beautifully speckled creatures look like they have been studded with coins. Of vast size but supremely gentle and curious, whale sharks can be sighted off the west coast of Mafia year round, but in particular from November to April, during which time a sighting is guaranteed nine times out of ten.

They can travel as far as 13,000km to find rich feeding grounds. With poor sight, whale sharks rely mainly on their sense of smell to find food. For now, boat trips avoid the aggressive chasing tactics adopted by some boat captains on Zanzibar when tourists are trying to spot dolphins, and are an altogether calmer experience.

To give an idea of the size of these creatures, also known as basking sharks, they are typically about 12 metres long. Nobody really knows what age whale sharks live until, but estimates suggest they could live to as old as 60 years. They tend to feed on plankton, but also suck up other larger prey such as small crustaceans and fish.

With awesome mouths that can be as large as 1.5 metres, whale sharks look scary but are fairly placid unless provoked – in rare cases they have been known to butt sport fishing boats.

Speak to your hotel to organise a whale shark expedition, which can be combined with a picnic lunch and visit to some other sites on the west of the island. Try not to hassle the boat captain about finding whale sharks - he is doing his best to find them for you, and it's better that the kind of chasing behaviour that happens in Zanzibar is avoided on Mafia.