Comino Island is a tiny island between Malta and Gozo that is accessible from both islands. From the port of Mgarr (Gozo) and from Cirkewwa (Malta) there are many fast boats that will come out to Comino for about 15 euros roundtrip. There you will find this island with clear water. Try to avoid going on the weekend because there are so many tourists there you will feel packed in and overwhelmed.
Here's a photo so you get the idea of the Blue Lagoon on Comino Island, Malta. It's an amazing and beautiful place though it does get a bit too crowded in summer. Even so, it's worth the trip just to see the color of the water and take a refreshing dip.
These are some seriously clear Mediterranean waters. It's on the smallest island of the Maltese archipelago and was the site of many famous battles between the Christians and Ottomans. It's a gorgeous place that's totally undeveloped except for a single hotel.
