You find yourself on a limestone reef with the characteristic big boulders covered with marine flaura and fauna.
Open Water divers will follow this wall out to sea, where it drops away to depths in excess of 40m. You will follow the wall down to a depth of 18m, swimming over the reef which is home to large octopus, grouper, parrotfish and sea bream. On reach 18m, you will swim away from the wall and follow the reef around in a semi-circle along the 18m contour. The reef will then gradually get shallow, taking you back up to a depth of around 10m and you find yourself facing another huge cliff wall, extending up above the surface.
Turning right along this wall takes you into the "Third Cave" - a huge cavern (there is always air above you if you need to surface) which extends 50m inside the mountain, a depth of around 12m. As you swim inside, you see the beautiful colours of soft corals and sponges on the walls of the cave. Moray eels are often seen hiding in rocks on the floor of the cave and many small wrasse and other fish near the walls. On reaching the back of the cave, you turn around and head back out, finishing your dive with a safety stop at 5m on a shallow part of the reef to the left of the cave.
Advanced divers can make a fantastic cave dive here also. Because it's a deep cave, you will need at least 40 dives to be able to make this dive. Following the same wall as the Open Water divers do above, you follow the wall to a depth of 28 metres. You will see a deep hole in the wall, approximately 2 metres across - this is the entrance to the first of the Keri Caves. Swimming inside, you will see a tunnel leading ahead of you.
The tunnel forks left and right after 5m or so. The right fork enters a deep cave system which extends over a hundred metres inside the mountain and is therefore a cave we consider too technical for recreational divers. However, looking down the tunnel to the right, you can often see dozens of translucent shrimps covering the cave walls and sometimes sleek, black catfish which feed eagerly on the shrimps.
Instead, you follow the guide to the left, through a narrowish tunnel (single file required) into a large cave chamber, which you enter at 26m and slopes upwards to 18m. The walls of the cave are covered with sponges and again there are often plenty of shrimps in here. At 18m, you see daylight flooding in from a deep crack in the wall, through which you will exit the first cave.
You then swim across the reef, from 18m to 10m, often seeing octopus, grouper and other reef life en-route. You then reach the second cliff wall and the entrance to the second cave - the "Bat Cave". Following a tunnel from 10m up to 5m, you find yourself in a vast chamber inside the mountain.
After making a safety stop inside the cave, the guide will signal you to go up! No, he's not crazy, you are in a chamber inside the mountain with air above you. The last 2m of water before the surface are suddenly colder and the visibility noticably less. This is because you have reached a freshwater layer on the surface of the sea!
Finally, you reach the surface, and shining you torch around, find yourself in a vast chamber. A crack in the roof, allows in daylight and shining your torch around the cave (from August to October), you will see why the cave gets its name - bats nesting in the cavern begin flying around inside the chamber!
You finish up the dive by descending down to 5m and bobbing out of the cave entrance.