Grotta Azzurra
Ustica Island · Italy
Ustica's Blue Cave is not the famous Capri version — it is a diver's cave, entered underwater and opening into an air-filled chamber where sunlight filters through submerged cracks to cast cobalt and silver light across walls encrusted with sponges, bryozoans, and the delicate pink tubes of serpulid worms. The transition from the sunlit entry to the cave interior is one of the most visually dramatic moments in Mediterranean diving.
Conditions
Depth
3 to 18 m
Good for beginners
Current
Usually still
Can pick up on the edge
Visibility
20 to 30 m
Clearest in the calm season
Water
14 to 28°C
3mm wetsuit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 14 | 14 | 14 | 15 | 18 | 21 | 24 | 25 | 24 | 21 | 18 | 15 |
| Vis (m) | 15 | 15 | 15 | 15 | 20 | 20 | 20 | 20 | 20 | 20 | 15 | 15 |
| Current | Still | Still | Still | Still | Still | Still | Still | Still | Still | Still | Still | Still |
Your chances of seeing each animal
Sponge community
Last confirmed Aug 17, 2024 · 6 records
Very likely
Most dives
Cardinal fish
Last confirmed Aug 18, 2024 · 6 records
Very likely
Most dives
Dusky Grouper
Last confirmed Jul 14, 2025 · 21 records
Likely
About 6 in 10 dives
Purple Sea Star
Last confirmed Jul 14, 2025 · 16 records
Likely
About 6 in 10 dives
Serpulid tubeworm
Last confirmed Aug 14, 2024 · 1 records
Likely
About 6 in 10 dives
Spiny lobster
Last confirmed Apr 27, 2025 · 1 records
Likely
About 6 in 10 dives
Ornate Wrasse
Last confirmed Jul 14, 2025 · 9 records
Likely
About 6 in 10 dives
Common Two-Banded Seabream
Last confirmed Jul 11, 2025 · 9 records
Likely
About 6 in 10 dives
Gear