When divers explore this limestone sinkhole they will find a distinctive geological formation that is a popular tourist attraction in the Maltese islands.
This guide explains where to find the Blue Hole dive site at Dwejra Bay, and why swimming and free diving inside a large sheltered rock pool is a focal point for so many visitors.
It took thousands of years of erosion, by wind and waves, to carve out this iconic circular rock formation.
Dive ten metres down, and you will find a narrow underwater arch that connects this natural wonder to the open sea.
So, how to get there?
This natural lagoon of blue seawater is located at a small village called Dwejra, on the western coastline of Gozo Island.
A 200 metre rocky cliff path leads down to the shore dive entry point.
Pro Tip: History suggests a geological fault in the limestone created the sea cave. Years later, the roof collapsed and left behind this inland sea and tunnel dive site that is popular with scuba divers and snorkelers.
You can't reach the entrance of the Blue Hole without walking over some ancient coralline limestone rocks. Hence, use caution when trekking over the sharp edges and rough surfaces.
A shallow shelf links the shoreline to the entry site. The sudden drop leads you to an archway and the site bottoms out at fifteen (15) metres.
There is also a large cave located at the bottom of the sinkhole (at the back). The spectacular scenery is one of the reasons why divers vote the Blue Hole as being among the best dive sites in the Maltese Archipelago.
A fringe of brown rock stretches most of the circumference of the 10-metre wide Blue Hole dive site. This provides some protection from the swells for divers and swimmers.
Even so, most of the dive sites in Gozo offer very little in the way of shelter from turbulent wave action.
Here's the thing:
Most dive schools will choose this site for an afternoon trip to escape strong winds and waves at other locations. Plus, this offers divers and good opportunity to see:
Pro Tip: You can experience the clearest visibility underwater from October to December. But, you will need some exposure suit protection against the cold water and an efficient dive torch for tight channels and swim-throughs.
In general, the diving at the Blue Hole at Gozo is for scuba divers and free-divers with some previous experience. So, the snorkeling enthusiasts should feel more comfortable at Coral Gardens instead.
These popular spots are close to the main sinkhole. You'll find large boulders scattered among the rocky outcrops at Coral Gardens. Average depths around the uneven plateaus range from a metre (4 feet) to ten (10) metres (32 feet).
The marine life is more abundant and diverse after climbing the fissure at the near vertical Chimney and ending up at Coral Gardens. So for example, it should be easy to catch sightings of:
Important: Watch out for Tuna speeding past above your head and be aware that jellyfish species might be in the area at certain times of the year.
Today, there's not much left of the original Azure Window in Dwejra (also called the Azure Alps). A heavy storm in March of 2017 caused the collapse of the structure.
Nonetheless, a new dive site called Azure Reef has replaced it. The adventure begins near to the surface and goes all the way down to forty (40) metres.
Scuba divers should be aware of large boulders with sharp edges dotted around the somewhat barren and infertile cave wall moonscape.
Pro Tips: Most of the local scuba shops will ask to see evidence of a diving certification (e.g. Open Water Diver, or Advanced Freediver). Other useful experience would include the PADI Cavern Diver certification and Nitrox Diver Specialty.
Pro Tip: This short video [6:11 seconds] contains some stunning footage about the popular dive sites at Dwejra, in Gozo.