There's more than fishes around the islands. Coral and green turtles are captured in this photo - can you spot the turtles?
The Great Barrier Reef is near Australia and this Manta Ray was snapped around an island within the reef.
Special cameras are being used and around 50 thousand snaps are being taken. This one was taken around the Philippines, a country in South-East Asia.
As well as being great for people to see what it's like underwater, the snaps will help scientists look at the different reefs around the world and keep an eye on how things are changing.
Now you can see deep down in the world's coral reefs thanks to Google Street View maps and the Catlin Seaview Survey which have been taking thousands of snaps of what lies beneath the waves. This is a scene below Heron Island in the Great Barrier Reef.
