Blue Lagoon / Alex’s Cave

 The famous Blue Lagoon on Comino is wonderful to snorkel, but with a depth of 3m is not the best dive.

However, within the large islet to the south of the lagoon is a remarkable underwater cave, including a chamber with fresh air, and suitable for all levels of diver. The surrounding area includes a pinnacle and a tunnel.

Your boat may anchor at the south end of the Blue Lagoon, or just outside near a small pinnacle that is known as Mushroom Rock. Either way you are very close to a beautiful underwater tunnel linking the lagoon to the sea, just at the easternmost point of the large islet containing the cave where the coast drops underwater to form a shallow reef. The tunnel is 4m deep on the lagoon end and has very interesting ledges on either side where you can usually find nudibranchs and often a large, patient scorpion fish or two. There is a large hole in the roof, which gives the tunnel a bright, airy feel and brings out the colours of the sponges, corals and bryozoa.

On leaving the tunnel at 8m you are directly in front of the Mushroom Rock. Swim over to this pinnacle where there is an interesting reef at its base, just above a an area of gravel at 12m. Both areas have lots of hiding places for octopus. Turn right and head towards the sandy seabed at 16m: on your right will be large underwater headland with a perfectly square notch cut out of it. The headland can hide morays while on the sand you should see pearly razor fish loitering around their holes. Although you cannot usually see the holes in the sand, approach too close and the razor fish will dart down into the sand and disappear.

Follow the boundary between sand and reef for a few minutes heading west and you will come to the cave entrance, just behind a large boulder. The entrance is very wide, and also very light seeing as the cave is open above the water for part of its length. You might hear and see small boats taking tourists a little way into the entrance 14m above you. The first leg of the cave is well lit due to a crack in the rock above, until you reach the left-hand bend where it becomes completely dark. Turn on the torches and explore the side walls and ceiling of this wonderful underwater chamber. It is 20m long and about 4m high and wide, and there is no way to get lost, plus you can always see the light of the entrance if you turn around. This makes Alex’s Cave a great first cave dive for those without experience, but bear in mind that the floor of the cave is fine sand, and so good bouyancy control is a must. The walls and ceiling contain plenty of shrimp, both with and without claws, and there is also a resident conger eel called Alex.

When you have reached a dead end, about 10m deep, slowly ascend to your right and you will find a chamber above sea-level with room enough for half a dozen divers at least. The air here is fresh, since there is a small crack through which you will see some sunlight. It is possible to squeeze through to the outside world, but definitely not while wearing scuba. If you have not thought to bring a picnic then you will have to descend again to 10m, taking it slowly to make sure there are no problems equalizing. Once your group is at the bottom I would suggest that everyone turns off their torches and enjoys the intense blue arch that is the exit.