Visitors arriving by ferry find Gialos unexpectedly serene, yet this quiet harbor is the wellspring of a grand maritime heritage. Symi is celebrated as the birthplace of Greek sponge diving, a tradition that stretches back centuries. In medieval times, observers noted that only Symians harvested sponges, leading some foreign travelers to believe that sponges grew nowhere else. Armed with nothing more than a heavy stone for ballast, Symian fishermen descended into the Aegean depths with remarkable skill. In 1840 the first documented Symian sponge diver, Michael Karanikis, sank 12–15 kg of stone (later called skandalopetra) and returned with a sponge, proving the legend true. By the late 1800s Symi’s armada of sponge boats exceeded 400 – at one point the largest fleet in the world.
Situated in the southeastern Aegean Sea, Symi is one of the Dodecanese islands. It lies about 41 km (25 miles) northwest of Rhodes, across a channel of sapphire water. The island’s terrain is rugged and mountainous, clothed in pine forests and Mediterranean shrubs. Symi’s main settlement is built on two levels: Yialos (Gialos) around the harbor, and Ano Symi higher up the hills. In its heyday Symi’s population exceeded 22,000, but by the 2021 census it had fallen to about 2,600. The climate is typically Greek – long, sunlit summers and cool winters – so that even in late afternoon the hillsides glow under the Aegean sun. Patrons of land or sea will often notice the salt tang on the breeze along with the aroma of pine from the slopes.
The main harbor district of Gialos is striking for its 19th-century stone houses and mansions. These grand Neoclassical buildings were financed by the sponge trade’s fortunes. Even today, pastel-painted villas and curved marble staircases face the waterfront. “As soon as I got off the ferry, I was drawn to the Neo-Classical mansions that lined the path beside the water,” one visitor writes. Many of these mansions were built by Symian benefactors – notably Georgios Petridis – in gratitude for the industry’s wealth. A short walk uphill leads to the 19th-century clock tower and the Petrideio School, monuments funded by that same Petrides family. Together, these landmarks speak of an era when sponge-export riches transformed Symi’s architecture.
Several factors explain why Symi, rather than any other island, dominated Greek sponge harvesting. The skill and knowledge of Symian divers were literally taught to others: local sources state that Symians “taught the other islanders how to fish, process and trade sponges”. Symi’s geography and history also gave it an edge. Under Ottoman rule it paid tribute in sponges rather than coin, recording that in 1522 the island delivered 12,000 large and 3,000 fine sponges to Constantinople. Meanwhile its privateers and merchants ranged widely: by the late 19th century Symian boats sold sponges from North Africa (e.g. Benghazi) all the way to Syros, London and New York. In effect, Symi’s entire economy revolved around this one natural resource, fueling the fortunes that shaped its towns and ships.
Symi’s sponge-diving tradition is rooted in antiquity, though hard data from before the 1800s is scarce. Ancient Greek sources allude to skilled freedivers, and experts note that by Aristotle’s era, breath-hold divers routinely exceeded 60 m (200 ft). In the Middle Ages and Ottoman period, outsiders remarked that only Symians collected sponges – seeing Symi’s boats at work, travelers assumed sponges grew nowhere else. Ottoman tax records underscore the island’s early prominence: in 1522 Symi delivered 12,000 coarse and 3,000 fine sponges as an annual levy. By the 18th century, Symians had perfected free-diving with stone weights. The first named Symian sponge diver was recorded much later: in 1840 Michael Karanikis descended with a 12–15 kg skandalopetra stone and returned from 20 fathoms under water with a sponge.
During the 19th century Symi’s sponge industry soared. With each passing decade, the island’s fleets grew: by 1896 about 440 Symian “scuba” boats operated – far more than any other Greek island. These vessels crisscrossed the Aegean, selling sponges through ports like Syros and Piraeus. Symi’s merchants even established agencies in Europe and America; for instance, the Petrides Brothers founded offices in Paris, London, and New York to market Symian sponges. The economic impact was visible everywhere on Symi: tavern-keepers, stonemasons and shipbuilders all prospered on the sponge profits. The harbor’s waterfront filled with merchants, and the town grew outward as the industry boomed.
The technology of sponge diving changed abruptly in 1863 when Symian Fotis Mastoridis returned from India with the first Mediterranean diving bell (hard suit). In a famous experiment, his wife Eugenia put on the heavy brass suit and submerged in Gialos harbour – the first such demonstration dive on a Greek island. Word spread quickly. Within a few years most Symian sponge boats carried a diving helmet, allowing divers to breathe underwater and reach deeper reefs than ever. This innovation dramatically increased sponge yields – but it also increased risks, as divers now faced the dangers of rapid descent and ascent without modern safety protocols.
By the late 19th century, the sponge business was dominated by the Symian merchant family of Petrides. Nikitas Petridis expanded his company across the Mediterranean, as evidenced by offices in Syros, Piraeus, Paris and London. Their wealth financed grand building projects back home. Notably, Symian benefactor Georgios Petridis endowed the Petrideio clock tower and school in Gialos – handsome Neoclassical institutions built with sponge fortune. In practical terms, Petrides ships still operating from Gialos collected sponges on the sea floor and returned through international ports. Their operation transformed Symi into a global exporter – an outcome that explains why even Victorian gentlemen in London might pay a premium for “sponges of Symi” on the market.
The prosperity of Symi’s sponge fleets ended in the early 20th century. During World War I, the Italian occupiers of the Dodecanese banned sponge harvesting, abruptly halting the industry. Afterward Symi never fully regained its lead: over the following decades divers and merchants gradually relocated to Kalymnos, a neighboring island which became Greece’s new sponge-fishing capital. As one recent account puts it, after World War II Symi “handed over the sponge diving baton to Kalymnos”. Today the story is largely told through museum displays rather than boats. Souvenir shops on Symi still sell natural sponges, but these come from Kalymnos and can last for years (often up to a decade) with proper care. Symi’s vibrant sponge-diving golden era remains alive mainly in memory – and in the sturdy sponges customers buy in Gialos.
The word skandalopetra comes from the Greek for “stone sandal,” a nod to its flat, hydrodynamic shape. A skandalopetra is typically a solid slab of granite or marble weighing 8–15 kg, with a hole for attaching a rope. When in the water, the stone becomes a one-way anchor: once the diver descends to the desired depth, the stone rests on the bottom and the diver pulls himself up on the rope. The diver then detaches the stone and resurfaces by hand-over-hand on the line. This simple yet ingenious design was used across the Mediterranean – but it was Symi that became legendary for it.
Skandalopetra diving is essentially gravity-powered freediving. A diver takes a deep breath and grips the weighted stone as shipmates drop it into the sea. Gravity quickly carries the diver down as the stone sinks; without the stone’s pull, a free diver of the same skill would descend more slowly. Once the diver gathers the sponges in a mesh bag, he signals the surface crew by tugging on the rope. That signal tells the crew to pull both stone and diver back up to the boat. The entire descent-and-ascent cycle is usually counted in seconds, with the diver spending only a minute or two underwater per dive. Seasoned Symian divers mastered it through practice and what modern research calls the “mammalian dive reflex,” rapidly slowing heart rate and conserving oxygen as soon as they hit the water.
The results could be astonishing. DAN’s historical survey notes Symian divers routinely plumbed depths of 60–70 m (200–230 ft). For instance, the Sarandaki brothers from Symi are recorded diving to 40 fathoms (about 240 ft) on one breath. In one famous case an untrained diver named Georgis Hatzis surfaced from 250 ft under water. These feats required only minutes underwater – often just 60–90 seconds – as divers quickly collected sponges and signaled for retrieval. By the late 1800s observers like British naval officer W.H. Spratt noted some Greek divers averaging 90–120 sec bottom-time at 50–60 m depths. In short, the Symians’ skandalopetra technique allowed free divers to reach depths that would be the envy of even modern champions.
Skandalopetra divers relied on the human body’s innate diving reflex. Within seconds of immersion, blood is shunted to the core and the heartbeat slows, conserving oxygen. Experts believe skilled freedivers may even develop larger spleens and blood volume with training; indeed, ancient sources recognized Greek divers for such adaptations as early as Aristotle’s time. Symian divers further conditioned themselves with “work-up dives” – repeatedly descending and surfacing during training to expand their tolerance for carbon dioxide and pressure changes. This regimen was crucial: without modern gear, pushing past 200 ft came at a cost. (The dangers of deep diving are discussed in the next section.)
In 1863 a Symian ship’s captain named Photis (Fotis) Mastoridis journeyed to Bombay (then under British rule) and acquired one of the first modern diving suits. The equipment was a brass “scaphander” – essentially a rigid air helmet with weighted boots and air hoses – and it was cutting-edge by the standards of the day. Mastoridis brought this suit back to Symi, effectively transferring a foreign innovation to the Aegean.
To prove that the scaphander was safe, Mastoridis’s wife Eugenia donned the heavy suit and submerged in the harbor of Gialos. Clad in copper helmet and weighted boots, Eugenia descended beneath the waves on that historic 1863 dive, then re-emerged alive and well, much to everyone’s astonishment. This demonstration captured the island’s imagination – it was symbiotically historic that a Symian woman first ventured under the new deep-sea technology.
News of the diving bell spread rapidly through Greek sponge-diving circles. By 1868, nearby Kalymnos had equipped 10 boats and 30 divers with suits; by 1869 it had 15 suits in use. In the next few years, scaphander technology was adopted on Symi, Kalymnos and across the Dodecanese. Its practical impact was immense: with breathing helmets, divers could stay submerged far longer and harvest sponges from much deeper reefs than before. Symi’s fishermen felt the difference immediately, retrieving sponges that would have been impossible to reach by freediving alone.
The downside of this new reach was a sharp rise in accidents. Early diving suits had no decompression chambers or procedures. Contemporary reports are chilling: in one 1867 season an observer noted that 10 out of 24 divers working in the region died or were disabled. Over the first half-century of scuba diving in Greek waters, some estimates place the death toll as high as 10,000. Local accounts attribute this to “the bends” (decompression sickness) and other pressure-related injuries. In other words, every gain in sponge yield came at a high human price – a sobering lesson from the era of the brass helmet.
Commercial Greek sponge diving traditionally focused on a few key species. Marine biologists list Symi’s common harvests as the honeycomb sponge (Spongia lamella, or kapadiko in Greek), the silk sponge (Spongia officinalis, known locally as matapas or fino), and the elephant-ear sponge (Hippospongia equina or Psathouri/Lagofito). Each has a distinctive texture and use:
Sponge Type | Greek Name | Texture / Pore Size | Typical Use |
Honeycomb sponge | Kapadiko | Large pores, coarse texture | Bathing, hard scrubbing |
Silk sponge | Matapas (fino) | Very fine pores, velvety soft | Facial cleansing, baby bathing |
Elephant ear sponge | Psathouri (lagofito) | Medium pores, firm texture | Exfoliation, household scrubbing |
Each species’ quality also depended on depth. Generally, sponges from greater depths are denser and more durable. For example, a deep-collected kapadiko will be darker and sturdier than a shallow one. After harvesting, sponges were carefully cleaned of all organic matter and then sun-dried or bleached to stabilize them. Only a living sponge yields the soft, absorbent product sold in shops; if the sponge is fully dried out or artificially whitened, it loses some of its elasticity.
Diver depth had a direct impact on sponge quality. Generally, sponges collected from greater depths were denser and more valuable. For example, shallow-water kapadiko might be softer and pale, whereas deep-water specimens (often called “silver” or “black” sponges) are darker and much more durable. Divers favored these deep hauls because a denser sponge would fetch a higher price on the market.
After harvest, sponges undergo careful processing. They are rinsed repeatedly to remove sand and organic tissue, then sometimes bleached lightly in sunlight or salt to even out color. Finally the sponges are hung to dry slowly. This traditional method ensures a supple, resilient texture. A well-processed natural sponge remains pliable for years – if kept clean and allowed to dry between uses, it can last a decade or more, far longer than typical synthetic sponges.
Sea sponges are not plants but simple animals – some of the oldest multicellular life on Earth. They have existed for roughly 600–700 million years, long before fish or corals. Structurally, a sponge is a network of channels and pores. Tiny cells create currents: water enters through numerous small pores and exits through larger openings. In this way sponges constantly filter the surrounding sea. Remarkably, a single kilogram of sponge can pump on the order of 20,000–24,000 liters of water per day. For perspective, sponges can draw in up to three times their own volume in water daily. This filtration has ecological value: by removing particulate matter, sponges help keep reef waters clear and recycle nutrients.
Sponges grow slowly. After a sponge is cut, leftover fragments of living tissue can reattach and regenerate given time and good conditions. Commercial sponges generally take about 1–2 years to regrow to harvest size under optimal conditions, which is why fishermen once rotated harvesting zones. In a healthy reef, sponge biomass can be quite large – in some Mediterranean gorges, divers report abundant sponge carpets. Sponges also house symbiotic algae and bacteria, contributing to local biodiversity. In short, Mediterranean sponges are living conduits of water and life, not merely inert bath linens.
In recent years natural sea sponges have been promoted as an eco-friendly alternative to synthetics. Unlike plastic kitchen pads, natural sponges are fully biodegradable and contain no microplastics. Indeed, environmental guides note that a well-kept sea sponge can last up to a decade, whereas synthetic foams usually begin to degrade within months. Natural sponges also avoid the chemical additives often found in manufactured products, and many users find them gentler on skin. Because of their open-cell structure, a sea sponge circulates and holds dozens of times its volume in water, producing a rich lather and making them feel softer when wet. Common uses range from body bathing (kapadiko sponges work well for showers) to fine arts (small fino sponges are used in watercolor painting). Choosing a natural sponge means choosing a product that is long-lived, renewable, and kind to the marine environment.
Feature | Natural Sponge | Synthetic Sponge |
Origin | Harvested from the sea | Manufactured from plastic |
Lifespan | Lasts many years (often 5–10+) | Usually weeks to months |
Environmental Impact | Biodegradable, sustainable | Contains microplastics (pollution) |
Hypoallergenic | Generally yes (no added chemicals) | May contain dyes or antimicrobials |
Common Uses | Bathing, cleaning, art | Household cleaning, scrubbing |
Symi is most easily reached from Rhodes. Ferries depart daily (more often in summer) from Rhodes’ Mandraki harbor to Symi’s Gialos, a trip of roughly 90 minutes. In summer months fast catamarans may reduce travel time, but schedules vary by operator and season. From Gialos port it is a short stroll to the village shops and waterfront – for Ano Symi one must climb or take a local taxi (about a 20-minute walk). As of 2025, ferries run year-round (albeit less frequently in winter), making day-tripping feasible.
The Symi Nautical Museum, housed in a grand 19th-century building in Ano Symi, is the island’s maritime showcase. Spread over three floors, it displays diving suits, reels, rope-making tools and historic photos of sponge fleets. Visitors can see the old hard-hat helmets, weighted skandalopetra stones, and even the ship’s anchors recovered from ancient wrecks. (Museum staff note: allow about 15–20 minutes to hike up from Gialos – the path is steep. If it’s very hot, consider taking a taxi or visiting early in the morning.)
Back down in Gialos, no Symi visit is complete without browsing the sponge shops. Nearly every souvenir store on the harbor sells natural sponges (often labeled “Greek sponge”) alongside olive-wood crafts and local honey. These sponges come packed in mesh or boxes to stay moist. Feel the texture: a genuine sea sponge is soft and springy when wet, unlike coarse synthetic pads. Shopkeepers typically display all three main types (kapadiko, fino, psathouri) and will gladly explain which sponge suits which purpose. They also advise testing a sponge by wetting it in a sink – an authentic sponge doubles in size and becomes plush when wet, whereas a fake or very old sponge will remain stiff. Prices vary with size and type – expect to pay more for larger, denser sponges (especially dark-colored deep-water types). The vendors emphasize that their sponges come from sustainable fisheries in Kalymnos, and that these authentic products can last up to a decade with proper care.
Symi’s clear waters and rocky coves invite exploration by boat. A popular plan is to take a daily excursion along the coast, stopping to swim or snorkel. If staying on land, a few beaches are accessible by path or short boat ride:
– Agia Marina (Ayia Marina): A pebble beach with umbrellas, reached by a 20-minute excursion boat from Gialos. Calm, shallow water and a nearby café make it family-friendly.
– Agios Georgios Dyssalonas: A tiny cove visible from Gialos. Adventurous visitors sometimes jump off the cliff into clear water here (the drop is up to 15–20 meters) for a thrill.
– Nimborio: A quiet bay north of Gialos (about a 10-minute walk). Its shallow sandy bottom is easy on the feet, with stone huts for shade.
– Marathounda: A remote golden-sand beach on the west side, reachable only by private boat or a rugged hike. Its seclusion rewards visitors with crowd-free swimming.
Symi is busiest in summer, not just for the weather but also for its cultural festival. Since 1995 the island has hosted the Symi Festival of music and dance every July–September. Concerts (often free) are held in open-air venues like castle ruins or village squares, featuring classical, folk and jazz performances. Travelers aiming for a July or August trip should reserve accommodation and ferry seats well in advance, as the island fills up during the festival. The later summer season, though hot, offers the richest program of events. Cooler shoulder seasons (May–June or late September) have fewer events but still pleasant swimming weather. Whenever you visit, local guesthouses and tavernas will gladly share stories about the sponge era over a plate of fresh seafood or local cheese.
After all that history, shoppers on Symi naturally wonder: how to pick a good sponge? Here are some tips from local experts:
Symi’s sponge legacy even crossed the Atlantic. In the early 1900s American entrepreneurs brought Greek sponge divers (many from Symi and Kalymnos) to Florida’s Gulf Coast. By the 1940s the Greek community in Tarpon Springs, Florida, had grown so large that the town advertised itself as the “Sponge Capital of the World.” In fact, records show Tarpon Springs at one time hosted about 100 sponge boats and roughly 1,000 Greek divers. The Greek techniques (including scaphander diving) transformed Florida’s sponge trade, making it internationally competitive. After 1985 a disease devastated the sponge beds, bringing that era to an end, but the Greek influence remains in Tarpon’s architecture and festivals. Tarpon Springs celebrates its history with annual events and a Sponge Docks museum, echoing Symi’s own heritage displays.
Although commercial sponge diving is a relic of the past in both countries, the cultural bonds endure. Symi and Tarpon Springs are official sister cities as of 2008 – a testament to their shared heritage. In both places, sponge museums recount the same stories of daring divers and floating markets. For travelers, visiting Tarpon Springs offers a parallel chapter in this saga: its old sponge boats and Greek bakeries will look familiar to anyone who’s browsed the quays of Gialos. Meanwhile back on Symi, the Nautical Museum and local storytellers keep the memory of those divers alive. Whether it’s a fisherman explaining how each sponge is harvested or a historian describing the island’s peak years, the dialogue between past and present is palpable.
Q: Is sponge diving still practiced in Symi today?
A: Sponge diving as a commercial industry no longer takes place in Symi. The practice effectively ended in the mid-20th century as divers moved to Kalymnos. Today you won’t see divers jumping from boats in Symi – instead the heritage is commemorated in the Nautical Museum and local shops. (Natural sea sponges are still sold in Symi’s harbor shops, but these now come from Kalymnos.)
Q: How long can natural sea sponges last?
A: Natural sea sponges are quite durable when properly cared for. High-quality Mediterranean sponges can last many years – often up to a decade of regular use. Their robust internal network resists tearing and degradation. With rinse-and-air-dry maintenance between uses, a genuine natural sponge will outlast most synthetic alternatives.
Q: What is the difference between Symi and Kalymnos sponges?
A: There is virtually no inherent difference in the sponge itself – the same species grow around Symi and Kalymnos. The distinction is mainly historical and geographical. Symi used to be the center of sponge harvesting, but after World War II the focus shifted to Kalymnos. Modern “Kalymnos sponges” are essentially the same products that once came from Symi’s waters. Any variation is subtle (due to depth or season) rather than fundamental. In practice, sponges labeled “Greek sponge” in Symi usually originate from Kalymnos today.
Q: How deep could skandalopetra divers go?
A: Symian freedivers achieved astonishing depths. Historical records report dives to over 200 ft. For example, two Symian brothers reportedly reached 40 fathoms (about 240 ft) on a single breath. Another account mentions a diver surfacing from 250 ft under water. Typically, skilled Symian freedivers could reliably reach around 60–70 m (200–230 ft) with the stone-weight technique, depending on conditions and training.
Q: Are sea sponges alive when harvested?
A: Yes, sea sponges are living animals (simple multicellular organisms). When divers cut them from the sea floor, the harvested portion is technically alive; its skeletal structure and some living cells remain viable. Only the sponge’s “skeleton” is sold, but some tissue may regrow. Indeed, fragments of sponge left in water can reattach and grow if conditions allow. In contrast, a synthetic sponge was never alive.
Q: Can a visitor buy authentic sponges in Symi?
A: Absolutely. The best place to purchase genuine natural sponges is along the Gialos harbor waterfront. Many shops (often marked “sponge shop” or “souvenir”) display baskets of sponges outside. Vendors here sell directly to tourists, explaining the differences between sponge types and often allowing you to handle the products. Buying here ensures fresh stock and authenticity. (Keep in mind all Greek sponges now come from Kalymnos, but buying in Symi supports the local tradition and provides educational context.) A trustworthy seller will guarantee their sponges are 100% natural and sustainably harvested.
Q: What is the Symi Festival?
A: The Symi Festival is an annual summer arts festival (July–September) established in 1995. It features open-air concerts of classical, folk and jazz music, as well as dance and art exhibitions, often staged at scenic venues like castle ruins or village squares. The events are usually free and draw crowds from Rhodes and beyond. If you visit in July or August, you can experience live performances under the stars – just be sure to book your ferry and lodging well in advance, as the island gets busy during the festival months.
