Halfway between Croatia and Italy, in the middle of the open Adriatic, rises Palagruža – Croatia's most remote island that most people will never see. But those who dare to cross 68 nautical miles from Split or 26 from Komiža discover something no tourist guide mentions: a system of underwater caves that local fishermen have guarded as their best-kept secret for generations.
Why are Palagruža's caves so special?
Palagruža is no ordinary island. This is a volcanic archipelago over 200 million years old, and its geological structure has created a labyrinth of underwater cavities that exist nowhere else in the Adriatic. While most Adriatic islands have limestone structures with smooth caves, Palagruža is built from diabase and gabbro – dark volcanic rocks that erosion has shaped into grottoes of unusual forms and incredible depths.
Local fishermen from Komiža, who have fished around Palagruža since time immemorial, know these caves by heart. For them, they are not a tourist attraction – they are shelter from the bora wind, a place where lobsters gather, and a secret passed down from generation to generation.
4 grottoes that only local fishermen know
1. Vela Spilja – The Queen of the Depths
On the northwestern side of the island, about 15 meters below the surface, opens the entrance to Vela Spilja. Fishermen call it "The Queen" because its main chamber, nearly 30 meters wide, resembles a cathedral carved into stone.
Practical information:
- Entrance depth: 12-15 meters
- Total depth: up to 28 meters
- Visibility: average 25-40 meters (one of the best in the Adriatic)
- Difficulty: intermediate to advanced (AOWD diving certification or equivalent required)
Vela Spilja's specialty is the colonies of red coral growing on the ceilings deeper than 20 meters. This species has almost disappeared from the rest of the Adriatic, but here, far from human influence, it still thrives.
2. Komiška Rupa – The Hidden Passage
Fishermen from Komiža consider this cave "their own" because only those who grew up with stories from old gajetas know how to find the entrance. It's located on the eastern side of Vela Palagruža, and its special feature is that it passes through the entire cape – you can enter from one side and exit on the other.
What you'll see:
- A passage about 45 meters long
- A play of light creating incredible blue tones around noon
- Scorpionfish and blennies hunting small fish here
- Remains of amphorae (Palagruža was an important ancient station)
Tip from local fishermen: come between 11 AM and 1 PM when the sun is directly overhead. That's when rays penetrate through cracks in the ceiling and create an effect known as "blue fire."
3. Jastožera – The Treasure Chest
The name speaks for itself. This vertical cave at a depth of 8 to 22 meters has been known for centuries as the best lobster hunting spot in the entire Adriatic. Fishermen have kept it secret for generations, and the exact coordinates are still passed down only within families.
Why it's special:
- A vertical entrance that opens into a room the size of a small apartment
- Constant water temperature of 16°C even in summer
- Crevices hiding lobsters, as well as shrimp and spider crabs
Note: commercial lobster fishing is prohibited from September 1 to May 31, and Palagruža is otherwise a protected area. Diving is allowed, but fishing without a special permit is not.
4. Galebova Rupa – For the Brave Only
The most difficult to access and the most spectacular of all. Galebova Rupa is located on Mala Palagruža, a smaller islet 500 meters west of the main island. Entry is possible only in calm seas because currents here can be unpredictable.
Details for divers:
- Depth: 6-35 meters
- Length: about 60 meters
- Required: advanced certification, local guide, ideal conditions
- Best period: June to mid-September
The interior of Galebova Rupa is home to colonies of sea bass that grow to impressive sizes here because no one fishes them. Fishermen say they've seen specimens weighing over 10 kilograms.
How to actually get to Palagruža?
This is not a trip for spontaneous decisions. Palagruža requires planning, favorable weather conditions, and a good dose of adventurous spirit.
Transportation options:
- Organized trip from Komiža: Several local captains offer one-day or two-day trips. Prices range from 150 to 250 euros per person, depending on the group and program.
- Your own vessel: You need experience and a vessel capable of open sea. The crossing from Komiža takes 3-4 hours under favorable conditions.
- Diving safari: Diving centers from Vis organize multi-day diving expeditions that include Palagruža. Prices for a three-day safari range around 600-800 euros with equipment included.
When to visit Palagruža's underwater caves
The window for a safe visit is relatively short. The sea around Palagruža is known for its unpredictability, and access to the caves requires near-perfect conditions.
Ideal period: from June 15 to September 15
Optimal conditions:
- Wind less than 10 knots
- Waves up to 0.5 meters
- Underwater visibility over 20 meters
May and early June can be good, but water temperature is still around 18°C. True lovers of clear waters aim for mid-September when tourism has subsided, but the sea is still warm.
Accommodation and base for exploration
On Palagruža itself, accommodation is limited to a lighthouse that accepts a small number of guests (reservation required months in advance). For most visitors, the best strategy is to use Vis or Komiža as a base.
Komiža is the ideal choice because all trips to Palagruža depart from here. This fishing town offers an authentic Dalmatian atmosphere, excellent fish in local taverns, and peace that has become rare in the rest of the Adriatic.
Find accommodation in Komiža or on Vis through platforms specializing in the Adriatic and book at least a week – you'll need flexibility to wait for perfect conditions for the trip to Palagruža.
Tips from local fishermen for divers
The fishermen we spoke with share several tips you won't find in diving manuals:
- "The sea around Palagruža lies" – the surface may look calm while strong currents flow beneath. Always dive with a local guide the first time.
- "The caves remember" – don't touch anything. Corals, sponges, and marine organisms grow for centuries. One careless movement can destroy what took generations to form.
- "Thursday is for Palagruža" – old fishing wisdom says Thursday is the best day for the trip because Wednesday traditionally brings a change in weather.
Is it worth the effort?
Palagruža is not for everyone. It's far, it's demanding, and many conditions need to align. But those who arrive and dive into its caves return changed. This is diving as it was before mass tourism – wild, unexplored, and authentic.
Local fishermen like to say: "Palagruža shows you who you really are." Maybe they're exaggerating. But maybe not.
One thing is certain – these four caves hold secrets worth discovering. Just remember that you are guests in a place that has belonged to the sea and fishermen for generations. Behave accordingly.