Mathraki Island, Greece: A Swimming and Nature Adventure

In May 2023, I was lucky to travel to the Greek island of Mathraki to join a Long Swims Week organized by British swim tour operator SwimQuest. As part of my swimming training for the English Channel, this week was the perfect opportunity to swim a lot of distance over a few days and see how my body would hold up. What I did not expect, but was thrilled to enjoy, was such a beautiful natural environment rich with diverse flora and fauna, both underwater and on land. I discussed the island’s geography, people and food in a separate post. Here, I invite you on a journey of nature and swimming.

Overview of the Long Swims Week on Mathraki

Over the course of five days, I swam a total of 40 km / 25 miles, something I’d never done before. For some perspective, if I swam the English Channel in a straight line, which won’t happen, the overall distance would be 36 km or 21 miles. Mind you, I will have to do that all in one go, not over the course of five days, and with the uncertainties of currents, winds and tides in colder water.

Day 1: 6km around Mathraki

At 7am, we met for a pre-breakfast quick dip so that Patricia, our guide, could film us swimming a few strokes. The air was still fresh and we lined up for our stroke analysis shoots, which were quickly over. Our technique would be analyzed in the evening on a TV screen.

Morning Swim

After breakfast, we met again at 10am, now ready for our first swim. The last time I swam in the Mediterranean sea was in April 2023, a cold, miserable, and dispiriting experience that set the bar fairly low. I had good hopes that this Greek week would help boost my swim confidence and get me back on amicable terms with the sea. After all, ocean swimming is meant to be magic, when the water feels so alive and full of energy that you relinquish all control over your surroundings and find your own mental space. 

Thus it was with a mix of fear and excitement that I got into an old VW minibus in my swimsuit, sunscreen and sun hat on. The minibus took us to the main harbor, north of the hotel, where our group of eight swimmers was split into two groups on two boats. Our first swim would last just over an hour, so I switched on my GoPro, ready to do some filming on the go. Before we boarded the boats, we were surprised to hear singing voices. Could there be a Sunday kids’ choir on Mathraki? We found our answer the following night.

Sliding into the water from the boat, I looked around underwater. We were maybe 5 to 10 m (15 to 30 ft) above the sandy seabed and swimming, I could see straight down to the bottom. The water was surprisingly crystal clear and blue. It was, also, very empty of any sea life. Where were all the fish, the marine life, the seaweed? We later found out that there was plenty of it, but not here. That 2.5k leg only took 1 hour and 3 minutes to swim, from the harbor to the hotel.

Throughout the week, these were my favorite swims––starting from or ending up at the hotel. What a luxury to be able to swim to or from your front step, right?

Afternoon Swim

After a delicious lunch and the first of many Greek salads with fresh feta, we started from the hotel and swam out of the cove to follow the coastline. Then came my first encounter with Pelagia noctiluca. “Jellyfish!” I yelled, after being stung on the chest and the hand. 

The burning sensation was similar to that of stinging nettles but even though it stung, it wasn’t so bad that I wanted to get out for the day. I swam out to sea, giving a wide berth to the shallows where sometimes the jellyfish got stuck, and breathed a sigh of relief when they became more rare.

As we would find out, mauve stingers, the local flavor of jellyfish, thrived all around Mathraki and its surrounding islands, either as isolated individuals on the surface, or in large numbers in shallow rocky reefs. Mostly, they were so deep that we just swam over them and watched them being swished away by the currents.

Unfortunately, now with the paucity of predators such as sea turtles, jellyfish have become a serious issue in some parts of the Mediterranean, where they’re so numerous that bathing is impossible. Luckily, it wasn’t that bad around Mathraki.

The afternoon swim was choppier, windier, and slightly longer too. After a dreamy rocky cove where we relaxed a few minutes, we were back at sea and kept following the coast to swim out to a nearby island, roughly one third of the way up the north coast. 

After 2 hours and 35 minutes for 3.5k, I got back on the boat and we returned to the hotel.

The evening stroke analysis clinic was very informative, as we benefited not only from our guides Paul and Patricia’s experience, but from Lawrence, swim coach, Cerian, waterpolo player, and Boris, long-distance swimmer. 

Day 2: 8.4km around Mathraki, and from Platia to Trachia

That morning, Dimitri (of weed-whacking fame, read more on him here) started at the crack of dawn, waking a few of us up with the sweet sound of his weed-whacker’s engine. Since there was no getting back to sleep, I worked a bit before breakfast, trying to forget the all-night headache that hammered my head and made even the sound of the sea unbearable. Lo and behold, the wifi was terrible, so I got up.

Morning Swim

The morning swim started at the main harbor, up the east coast, over the tip of the island and down the west coast. With this third swim, we had effectively circumnavigated Mathraki in three separate chunks. This last stretch was absolutely gorgeous, with a long sandy bay peppered with boulders barely emerging above water. Down below, it had the feel of an underwater playground and obstacle course all in one. 

It was probably poor training for the English Channel––where there’s nothing much to see––as here, there was so much to see underwater: seagrass meadows (Posidonia oceanica), schools of little black fish, silvery long fish, sea anemones. I couldn’t help taking in every single movement, color, or shape. On a different note, I think that I was projecting Ancient Greek mythology fantasies, as I thought I saw broken Ionian columns in the Ionian Sea. Surely, I was dreaming.

More likely, they were funny-shaped boulders. Around the tip of the island, I swam into a thick swarm of jellyfish above shallow reefs. Sting. Sting. I swam out to the support boat shouting “Jellyfish!” at the top of my lungs, so Patricia could radio Paul on the other support boat and reroute swimmers behind me. Ouch, not all of them got the message in time. We didn’t know it then, but this was the last serious run-in with jellyfish. From then on, we wouldn’t see too many. 

This morning swim, coming in at 2 hours 13 minutes for 4.2k, ended at the main harbor, where we boarded the boat to get back to the hotel for lunch.

Afternoon Swim

If you saw The Big Blue, a 1988 French movie about extreme freediving in Greek and Sicilian waters, you might remember breathtaking underwater shots where the water is blue for as far down as the eye can see. This kind of blue has an otherworldly quality, one we were lucky to experience during our first dip that afternoon.

George, Paul and Patricia took our merry band of swimmers to a spot they called The Big Blue, where we could jump in the water and look around. This was not a swim per se, but a taste of the sea at its barest, a dip to enjoy sun rays shining down into the sea with nothing else around. Looking down without seeing the bottom was slightly unnerving, it all seemed so deep, but I kept a cool head. Since we could goof around, we did and ended up with some funny underwater portraits like this one.

After 20 minutes of bobbing around, we got back on the boat to reach the first island, where we were dropped in the water. 

Ahead of me were Platia and Trachia, which from under the sea, seemed like two mountains rising from the sea bed, with only their summital ridges surfacing above the water. Swimming from one island to the other, I felt that I was crossing a deep valley separating them. I realized, if not for this water, they would be part of the same landmass. Granted, they did share the same features––low rocky shore, a few hardy green plants, colonies of nesting seabirds, and plenty of sealife living in underwater seagrass meadows and rocky reefs.

We got a nice lift from favorable currents, which gently ushered us from one island to the other as if by an invisible sea hand.The afternoon swim, 4.2k, took 1 hour and 33 minutes. 

Dolphin Evening on Mathraki

For dinner, we went on a field trip to the neighboring taverna, where we were treated to musical entertainment by Austrian musicians and the choir of Austrian and German women they were tutoring that week. It dawned on all of us––these were the singing voices we’d heard the day before. To us, they became known as “the singers” and to them, we were “the swimmers”. There was much excitement at both groups of tourists mingling on this tiny Greek island, under the amused eye of locals. 

At dusk, while we were listening to a song, we saw some choir ladies stand up and yell, “Dolphins!”. Rushing to the edge of the terrace, we joined them as they pointed to the sea beyond the harbor.

In the distance, we spotted two dorsal fins diving underwater and a few seconds later, saw two dolphins jump out of the water. As serendipity would have it, the taverna was called “Dolfin.” Maybe the Austrian singer was right when he said—upon losing his audience mid-set—“Come on, guys! The dolphins come every night. I’m only singing tonight.”

The dolphins were too far away for us to see them clearly, so I couldn’t ID them, but they would most likely have been common bottlenose dolphins (Tursiops truncatus). In the sea of Corfu, two other species of dolphins live––the zebra dolphin (Stenella coeruleoalba) and the short beaked common dolphin (Delphinus delphis). All these dolphins live near the shores and like to follow ships and boats.

Needless to say, we were as excited as kids in a candy store. After dinner, Vanessa and Boris walked back to the hotel instead of getting on the VW minibus and were treated to nocturnal ballet of fireflies on the hillside. 

Day 3: 9.4k Mathraki Swim Circumnavigation

Day 3 was to be our big swim, the swim of all swims, where we would circumnavigate the island of Mathraki––10k total. Paul consulted George in the morning––should we swim clockwise or counterclockwise? George considered the currents throughout the day, winds, and recommended that we swim clockwise. 

As we swam at varying speeds, the logistics over 10k for a group of eight swimmers were more complicated than over 4k. Kim-Leigh and I would go first, supported by Vanessa on a sea kayak. Julia would go next, supported by Patricia on a sea kayak. Boris, Lawrence and Cerian would go last as a pod, supported by George on a motorboat. Paul would zip between all groups on the second motor boat. 

I was happy that we had already scouted the itinerary over the past two days. We’d know what to expect, what to look for, what to do. During the swim, Vanessa suggested I try out the kind of feeds and rhythm that swimmers use during the English Channel swims. The feeds would start at 1 hour and then go on every half hour. I would drink maltodextrin in a squeezy sports bottle and eat jelly babies and bananas. She gave me a 5-minute signal with her hand before each feed, let me catch up and stopped to throw the bottle in the water. I drank, treading water as quickly as possible, and if I dawdled, Vanessa spurred me on with an energetic, “Go! Go! Off you go!” Back to swimming I went. 

After the main harbor, we were a little ways out in the sea when we hit a strong head current. The current slowed us down so much that I stayed level with the same building on shore for 10 to 15 minutes! As we were going nowhere, I suggested we swim closer to the island. Luckily, this worked; the current weakened and I was able to move forward again, tracking my progress on the sea floor––seagrass meadow after seagrass meadow. At last,  we saw the cove of the hotel get closer, open up, and we swam across the sandy cove to the beach where the others were waiting for us. What a swim! 

Squid & Fireflies

That afternoon, after we had showered and had a late lunch, we were lounging around on the terrace. Suddenly, we were alerted by Vanessa that a large animal was swimming close to shore. None of us could tell what it was. A dolphin, maybe? No. A seal, then? No. How about a shark? Again, no. The creature poked its weird flat or triangular head once or twice out of the water and its long dark body was as large as a sea mammal, yet clearly it was something else.

Boris walked down to the beach to see it for himself.

It was a giant squid, roughly human child-size. What a truly remarkable sight. Disturbingly, it was too close to shore and too slow to react, which led us to suspect it wasn’t doing great. It turned out that one of its tentacles was badly injured and the squid was fished out by locals.

Out of the water, we saw its red tentacles and head where two round lidless eyes stared at us as it was slowly asphyxiating. It was both sad and fascinating, some of us saying that the squid should be returned to the sea, others arguing that it wasn’t our place to interfere with Greek island life. 

That cast a pall over our earlier exhilaration post round-island swim. Most of us had watched My Octopus Teacher, the Netflix documentary on a swimmer and an octopus, and felt compassion for the squid, but alas it was too late. 

That night, after dinner, we decided to go on a night walk to observe the fireflies mentioned by Vanessa and Boris. We were quite giddy, as fireflies are not very common anymore. Fireflies! When was the last time I saw fireflies? I tried to jog my memory. I must have been a teenager on the lake of Nakhon Sawan in Thailand, on a birdwatching trip with the school’s German teacher. It had been decades and I hadn’t seen any fireflies since. 

Sure enough, there they were: tiny insects darting to and fro, dancing in the shrubs, flashing on and off in the night, much to our delight. It was truly magical and that night, I went to bed with sparkles in my eyes, shadowed by thoughts of a squid’s last breaths.

Day 4: 6.3 around the Diaplo archipelago and Corfu

Did Dimitri have a lie-in? The weed-whacker only started at 8.30am when we sat down for breakfast. We almost missed its sweet noise to wake us up.

Morning Swim: Diaplo

What a dream the islands of Diaplo’s archipelago were. Separated by a shallow lagoon, the two biggest islands featured turquoise waters and such abundant sea life and cool limestone formations that some of us were later distracted from swimming. 

After being dropped off in the lagoon, we made our way to one of the sea caves in front of us, swimming in cautiously, as light became dimmer towards the back, and paying attention not to step on potential sea urchins. 

Sea caves are a dream, I love sea caves. They always appeal to my inner child and in this one, I could hardly contain my excitement. All good things must end, sadly, and we couldn’t play in the cave forever. Vanessa, Boris, Julia and I swam out of the cave to circumnavigate the smaller island in tourist mode. Every so often, we stopped to pause and take in the views, to spot a red starfish or to get as close as possible to the rocky hillside sloping into the sea. 

At one point, Vanessa was ahead of me and as I took a breather, she told me “Go! Go! Go!”. What?! Not fair. After the previous day’s big swim, I felt that I deserved some slack and strongly protested, arguing that the island was too beautiful not to go slowly. “Go! Go! Go!” she repeated, except she was pointing at the island. Puzzled, I removed my fogged-in swimming goggles and understood what she was saying––swim ear plugs don’t help. “Goats! Goats! Goats!” She had been showing me a small herd of wild goats skipping on the rocks on the island. Oh, what a laugh!

Julia had joined us by then and all three of us bobbed around a couple of minutes, delighted by the skipping goats. In a shallow creek a bit further, Patricia and Vanessa’s daughter were doing freediving competitions, while Kim-Leigh was documenting everything with her phone. On the other side of the island, Cieran and Lawrence spotted a brown red octopus playing hide and seek under a rock. Diaplo was a true nautical playground.

That morning swim came in at 1 hour and 18 minutes for 2.1km.

Afternoon Swim: Corfu to Diaplo

At lunch time at a coastal tourist town in Corfu, we bid Kim-Leigh goodbye (she was flying back to London) and had a meal at a local taverna. We all agreed that the food was a far cry from Nora’s home cooking, while discussing the afternoon swim plans. The initial plan was to drop us by boat at the end of the bigger Diaplo island and swim around the archipelago of islets. Lawrence came up with quick distance estimates, showing us that Corfu was only a mile from the island. Why not swim there? And so we did. 

Julia and I followed each other, Cieran, Lawrence, and Boris came after. At the island, Vanessa jumped in and joined me. After the tip of the island, we spotted Cieran, Lawrence and Boris in the water, as if they were looking down. As we got closer, Cieran exclaimed, “there’s a lionfish.” It hovered about 20 meters below the surface, quite still between two rocks, its wing-like fins spread out in the water. Oh, dear.

Highly invasive and poisonous, exotic lionfish have become a sign of warming oceans in the Mediterranean’s protected marine areas. Originally from the Indian Ocean, they decimate native fish species and reproduce at a worrying rate, replacing local fish stock. They’re, literally, the undesirable rabbits of the sea. 

We continued our swim and skirted the imposing cliffs of the bigger Diaplo island, much more ominous than its playing twin island. In this completely mineral environment, Vanessa and I swam together but at the end of the swim, there was some confusion as to where we should finish, so we kept going. In the end, Patricia whistled to get our attention and motioned us to quickly get on the boat. “We’ve seen lightning above Corfu, we need to leave!” 

The afternoon swim came in at 1 hour 50 minutes for 4.2 km.

Evening Meal at the Village on Top of Mathraki

Amazing meal at the taverna run by George’s auntie, where members of the extended family or neighbors came trickling in, some of them coming for introductions and chat. They were very welcoming and we realized that two of the older were fishermen. We must mention the lion fish! When we mentioned our lion fish sighting to them, they shrugged. Yes, lion fish, they’d seen them before and didn’t seem too alarmed. All of us thought they should be, but hey, what did we know. 

Day 5: 9k around Diakopos & Trahia

It was a dark and stormy night. I always think of Peanuts when I write that line, but it was literally a dark and stormy night. Some of us had trouble sleeping and enjoyed the biggest display of thunder and lightning above Corfu.

When I woke up, the air was cool and the ground still wet from the night’s rain. Before breakfast, I went for an early walk up to the promontory above our cove.

Up the hill, a quartet of white geese roamed free, patrolling the only road of Mathraki as if they owned it. They made good company for the stray cats and kittens of the island.

Morning Swim: Diakopos to Mathraki

This morning’s swim, we all agreed later, was “the longest 5k of our week”. We jumped in the water by Diakopos, and sighted on a shark tooth island called Karave, roughly half-way between Diakopos and Mathraki.

While the first half of the swim was smooth and peaceful, the second half, after Karave, took me completely off track, as I was pushed this way and that way by a strong head current and had to put up a fight. It was a relief when my hands finally touched the sand by the beach in front of the hotel. 

Afternoon Swim: Trahia to Mathraki

By the afternoon, we enjoyed favorable currents that carried us, as well as hundreds of jellyfish, to the west harbor of Mathraki. Paul was driving my support boat with Julia onboard, as she was taking a well-deserved break on that last day. After five continuous days of swimming, my arms were starting to feel heavy but that was not the reason I suddenly stopped a few hundred meters off the coast of Mathraki. “Road! There’s a road down below.” I swear, I could see linear arrangements of rocks forming two parallel––but interrupted––straight lines at the bottom of the sea. 

Unfortunately, the mystery was never solved. I think that I was mumbling, as neither Paul nor Julia heard me clearly, and by the time they got it, the current had pushed me beyond the mystery underwater road. 

When I was well within reach of the harbor, Paul instructed me to keep going, as he and Julia needed to take a different route with the boat. A few minutes later, I found them by the breakwall and got onboard. 

This concluded five days of intense swimming around the island of Mathraki.

Conclusion

When I signed up for SwimQuest’s Long Distance Swims week on Mathraki, I had no idea what I was getting into. It turned out to be the best decision I had ever taken in my English Channel journey. 

From a training perspective, it was a great way to swim slightly more than the English Channel over five days and see how my body was coping. For someone who loves nature as much as I do, Mathraki was a small paradise and I was truly delighted to discover this small island in great circumstances. 

However the best part, by far, was the wonderful human interactions during the trip. Whether surrounded by old friends or getting to know new friends, this week had been a rich experience––full of laughs, shared passions, and interesting discussions. In more ways than one, it was a break from my working days in front of a computer and I couldn’t wait to bring my girls to Mathraki one day, so they too can enjoy this secluded Greek island.