I was in Phuket on June last year diving with a bunch of tourists. At first I thought I won’t be seeing much interesting creatures as it was raining when we start descending.

After about 10 minutes, I was so amazed to see a group of Barracudas followed by a big Manta Ray, yes…I mean BIG!. It was a size of a van I can say, although our distance was about 15 meters, me and my dive buddies can see it clearly.

Manta Ray is the largest of rays. The largest known specimen was more than 7.6 metres (25 ft) across, with a weight of about 2,300 kilograms (5,100 lb). It ranges throughout tropical waters of the world, typically around coral reefs. They have the largest brain-to-body ratio of the sharks and rays.

The giant smalleye stingray on the other hand is a rare and elusive creature, winging quietly off the coast of Mozambique. Now, for the first time, this largest of the stingray species has been captured on film.

A BBC scuba diving crew grabbed a video of the smalleye, which is the largest and one of the rarest of the 70 species of stingray. The smalleye, which can grow to be more than two meters wide, was first discovered in 1908 and has been found alive only off the coast of Tofo, a small town in Southeastern Mozambique.

You can see the video at the BBC’s website, and the footage will also be part of the BBC Two documentary Andrea: Queen of the Mantas this Wednesday.