Illes Medes — What Forty Years of Marine Protection Look Like Underwater

I have been diving the Illes Medes since I was sixteen. Hundreds of dives, across every season, at every site. And what strikes me every time is not how beautiful it is — though it is — but how alive it is compared to unprotected coastline just a few kilometers away. That difference is the entire story of Medes.

Seven small islands, one nautical mile off L'Estartit, protected since 1983. What was once heavily fished limestone rock is now one of the most important marine reserves in the Mediterranean, and the largest in Catalunya. The reserve covers 511 hectares of sea and 21.5 hectares of terrestrial surface, all within the Parc Natural del Montgrí, les Illes Medes i el Baix Ter.

If you want to understand what marine protection actually achieves, come dive here.

Why Medes matters

Every marine reserve makes promises. Medes delivers on them, and the evidence is swimming right at you.

The reserve effect is measurable. The grouper population — Epinephelus marginatus — has grown continuously under four decades of protection. These are not small, skittish fish hiding in holes. They are large, confident animals that approach divers without hesitation. The Catalan diving community calls it "l'efecte reserva," and biologists study Medes specifically because the effect is so pronounced here. The population has even begun repopulating adjacent unprotected areas — a spillover effect that justifies the entire conservation model.

The habitat diversity is exceptional. The islands are a geological extension of the Montgrí massif, and the proximity to the Ter river mouth feeds nutrient-rich water into the system. The result: vertical walls draped in gorgonians, tunnel systems carved through limestone, Posidonia meadows on sand, and rocky reef at every depth. Each habitat supports different communities of species, which is why a week of diving here never feels repetitive.

The cave systems are Mediterranean rarities. La Vaca and Dofí offer underwater tunnel experiences that are genuinely uncommon in this sea. Not technical cave diving — these are illuminated, accessible passages that happen to be extraordinary.

The dive sites

There are over 21 named sites around the archipelago. I will not describe all of them — you would stop reading — but here is how I think about them after years of guiding divers through the area.

The sites every diver should know

Carall Bernat — The pinnacle that defines Medes diving. A limestone spike rising 72 meters above sea level, with walls dropping to 45-50 meters below. You circumnavigate it, and everything comes to you — gorgonians, groupers, pelagics in the blue. I have written about this site in much more detail separately. If you dive one site at Medes, make it this one.

La Vaca — A tunnel 30 meters long and about 5 meters wide, cutting straight through Meda Gran. Natural light enters from both ends, so you are never in darkness. There is a very large grouper — I have seen this individual for years — who stations himself near the entrance as if checking credentials. The tunnel itself is dramatic, but what surrounds it — walls rich with life, overhangs with spiny lobster — makes the entire dive excellent.

Dofí Nord — The most complex cave system at Medes. An air chamber at 10 meters, a short cave at 12, a longer one at 18-20 meters, and then "La Catedral" — a vaulted chamber that earns its name. Red coral grows on the cave walls, which tells you something about the water quality and the age of this ecosystem. Spiny lobster in the crevices. This dive rewards patience and attention to detail.

Tascó Gros and Tascó Petit — Two large rocks forming the northeast corner of the archipelago. Local divers call Tascó Petit "l'Aquàrium" and it is not an exaggeration — the density of fish life here is remarkable. These are also the best sites for eagle ray encounters in July and August. Depths reach 45 meters, but the shallower zones are equally productive.

For newer divers

Salpatxot — North of the islands, protected from most currents. This is where I take divers on their first Medes experience. The depth range — 5 to 25 meters — is comfortable, and the marine life is generous: groupers, morays, octopus. In June, moonfish sometimes appear here, which is a bonus nobody expects at a "beginner" site.

Punta Salina — On the Montgrí coast rather than the islands. A gentle sand slope, ideal for courses and try-dives. The diving is simpler, but you still encounter spiny lobster, morays, and octopus.

El Negre del Falaguer — Also on the coast, about 15 minutes by boat. A gentle slope that works well for less experienced divers while still offering the Mediterranean reef species.

For experienced divers

Pota de Llop — The deepest site at Medes, reaching 50 meters on the east coast of Meda Gran. Rocky cliff with gorgonians, a cave, conger eels at depth. This is where I go when I want to see the Medes that most visitors never reach. Experienced divers only — the depth and exposure demand it.

Pedra de Déu — Northeast of Meda Gran. The gorgonian walls here start at 15 meters and extend deep. Both Paramuricea clavata — the red/violet gorgonians — and Eunicella species in blue and yellow. Some of these fans are decades old. A centimeter of growth per year means the larger specimens predate the marine reserve itself. Big groupers patrol the base.

El Reggio — A 115-meter ferry intentionally sunk in 1991 to create artificial reef habitat. Now broken into three sections — stern, center, bow — sitting at 27 to 35 meters. The colonization by marine life has been impressive over three decades. Advanced divers only, and weather-dependent because of the exposed location.

And there are more

La Pedrosa has a 60-meter tunnel with a chimney exit. Les Ferranelles is a rock chain between Tascó Petit and Meda Gran that bursts with life — barracuda schools, moonfish in June, and a resident population of groupers. El Medellot, La Ferriola, El Rossinyol, Embarcador del Francès, Sant Istiu, Cap Castell, Puig de la Sardina — each with its own character. I have guided divers here for over a decade and I still find things that surprise me.

Marine life — what to expect and when

The residents

The grouper is the protagonist. Epinephelus marginatus is present at virtually every site, year-round. The Scubago database shows 612 logged sightings at Carall Bernat alone, peaking in July and August. But numbers do not capture the experience — these are animals that swim up to you, follow you along a wall, hover at arm's length. In an unprotected area, a grouper this size would flee at twenty meters distance. Here, they are curious.

Moray eels (Muraena helena) are in every rocky crevice. You will see several per dive without trying. Octopus (Octopus vulgaris) are everywhere if you know where to look — under ledges, in holes, occasionally out in the open doing their colour-change performance. Barracuda schools at the more exposed sites. Dentex — large silver predators — in pairs or small groups at depth. Spiny lobster in caves and crevices, nudibranchs on the gorgonian fans — the orange Cratena peregrina are the easiest to spot.

The walls themselves are habitat. The gorgonian coverage — Paramuricea clavata, Eunicella singularis, Eunicella cavolini, and white gorgonians — is what makes Medes walls visually distinctive from bare Mediterranean rock. Red coral (Corallium rubrum) in the cave systems, particularly at Dofí.

The seasonal visitors

Eagle rays (Myliobatis aquila) arrive in July and August, mostly at the Tascons and Ferranelles. They come from the open water side, so you need to be looking outward, not at the wall. When they appear, they are worth every moment of anticipation.

Sunfish (Mola mola) are occasional, especially in June. Not a reliable sighting, but one that changes your entire dive when it happens.

Tuna and bonito pass through when currents are running — pelagic visitors that remind you these small islands sit in open Mediterranean water.

What is changing

I want to be honest about this. The gorgonians — particularly the shallower colonies of Paramuricea clavata above 20 meters — have suffered from warm water events in recent summers. Heat stress causes tissue necrosis, and these organisms grow extremely slowly. The deeper colonies below 25 meters remain in good condition. This is not a reason to avoid Medes — it is a reason to dive here and understand what marine ecosystems face. Conservation is not abstract when you see it on the wall in front of you.

Conditions

The dive season runs April to November, with some centers offering winter dives by arrangement. In my experience, the best diving is June and September — warm enough for comfort, excellent marine life, and far fewer divers than the July-August peak.

Water temperature: Roughly 14°C in early spring, building to 24°C at the peak of summer. I dive in a 5mm suit from June to October, 7mm the rest of the season. Most visiting divers are comfortable in 5mm during summer.

Visibility: This is the Mediterranean, not the tropics. Some days are clear blue, some days are green. Summer generally brings better visibility, but I have had stunning winter dives with 25-meter visibility and murky August days. The marine life compensates on low-visibility days — everything is close to the wall.

Currents: Site-dependent and weather-dependent. The exposed sites — Carall Bernat, the Tascons, Pota de Llop — can develop strong currents, especially with the tramuntana. The currents bring pelagic species, so they are not entirely unwelcome. But they transform an easy dive into a demanding one. Your dive center decides site selection based on the day's conditions — trust their judgment, they do this every day.

Practical information

Permits and regulations

The Illes Medes is a regulated marine reserve. Every diver needs a permit issued by the Oficina de la Reserva Marina — your dive center handles this, but it means advance booking is essential, especially in summer when the daily diver limit fills up.

• Permit cost: 5.15€ per person
• Required documents: Dive certification (Open Water or equivalent), dive insurance (federation license or private)
• Beginners: Must be accompanied by a certified instructor
• Ecobriefing: Mandatory before each dive. Conservation rules: no touching marine life, maintain 1.5 meters from bottom and walls, no feeding. These rules exist because they work — the health of this reserve depends on diver behavior.

Dive centers

L'Estartit has around eight dive centers. They all operate in the same reserve and access the same sites. Differences come down to schedule, boat size, language, and guiding style.

• Unisub — the pioneer, operating since 1965
• Calypso Diving — PADI, strong sustainability commitment (CETS certified)
• Les Illes Hotel & Diving — hotel and dive center, four daily departures, SSI
• Xaloc Diving Center — SSI
• Aquàtica Illes Medes — own training pool, SSI, Mares equipment
• El Rei del Mar — family operation since 1990
• La Sirena — diving and snorkeling
• Orca Diving — based in nearby L'Escala

Many of these centers hold environmental certifications — CETS, ISO 14001, Mission Deep Blue (SSI), Longitude 181. It reflects a community that takes the reserve seriously, not just as a business asset but as something worth protecting.

Getting here

L'Estartit is about 50 km from Girona airport and 140 km from Barcelona. You will need a car. The town is small, built around the harbor, and everything dive-related is walkable once you arrive.

Pricing

A Medes dive with full equipment rental runs around 80-85€. Coast dives are slightly less. Night dive supplement around 25€, Nitrox around 3€ per dive. The park permit is typically included. These are indicative — check with your center for current rates.

A note on conservation

I guide divers here because I believe that showing people a healthy marine ecosystem is the most effective form of conservation education. When you see a grouper the size of your torso swimming toward you without fear, you understand viscerally what protection achieves. When you see a gorgonian fan that has been growing since before you were born, you understand what is at stake.

The Illes Medes reserve works. It has been working since 1983. The science supports it, the species counts confirm it, and you can see it with your own eyes on any dive. The best thing visiting divers can do is follow the ecobriefing rules, respect the distance guidelines, and leave the reserve exactly as they found it.

The honest summary

The Illes Medes is the best recreational diving I know in the western Mediterranean. Not because of any single spectacular feature, but because of consistency — the marine life density, the site variety, the infrastructure, the decades of protection that have allowed an ecosystem to recover and thrive.

If you are an experienced diver, the deep walls and cave systems will keep you coming back. If you are newer to diving, the shallow sites offer encounters with marine life that most Mediterranean divers never see. And if you care about conservation, Medes is proof that it works.

Come in June or September if you can. The water is warm, the marine life is excellent, and you will not be fighting for a permit with half of Europe.