Anti-submarine net of Cape Katsouni

Dive site

Max Depth: 55m | Temp.: 19°C (Oct-21)

Historical Context

On September 29, 1911, the Kingdom of Italy declared war against the Ottoman Empire under the pretext of protecting its trade in Tripolitania and Cyrenaica (modern-day Libya). However, the true cause of the war was the acquisition of the last province of the Ottoman Empire in North Africa, in line with the “Mare Nostrum” doctrine, which Italian nationalists had revived around 1880. This concept reflected Italy’s strategic security interests in the Mediterranean, stemming from its dominant geographical position, according to the geopolitical context of the time.

Italy, vastly superior to Turkey at sea, quickly occupied the coastal cities of Tripoli, Benghazi, Derna, and Tobruk. The Turkish forces withdrew inland but did not surrender and – in cooperation with the brutal Arab tribes – continued their resistance, achieving victories against the Italian expeditionary forces.

The prolongation of the war and Turkey’s refusal to capitulate, forced Italy to shift the conflict to other fronts in order to exert pressure. The Italian navy entered the strait of Dardanelles, while the Italian army advanced to occupy the Dodecanese archipelago.

The outbreak of the First Balkan War on October 5, 1912, changed the situation, and ten days later, the Sublime Porte was forced to sign the “First Treaty of Lausanne” at Ouchy Castle, in the Swiss city of the same name.

The treaty recognized Italy’s occupation of Libya while simultaneously stipulating the return of the Dodecanese Islands to Turkey, provided that Turkey ceases all hostile actions against the Italian administration in Libya.

The Ottoman Empire deliberately violated the terms of the Treaty to delay the possible transfer of the Dodecanese archipelago to Greece, thus favoring Italy’s continued presence there.

When World War I broke out, Turkey sided with the Central Powers in November 1914, while a few months later, in April 1915, Italy joined the Entente.

By the end of the Great War, the Kingdom of Italy was among the victors, with the Treaty of Sèvres, signed on August 10, 1920, cementing the dismemberment of the Ottoman Empire and awarding Italy the Dodecanese Islands and Kastellorizo.

The events that followed, with the “War of Independence” between the Turkish National Movement and the Allies of the Entente, including Greece and Armenia, led to the birth of the Turkish Republic and the complete defeat of the Greek army in Smyrna.

After intense disputes and negotiations, the Treaty of Lausanne was signed on July 24, 1923, following the Second International Conference of Lausanne. In one of its articles, the Treaty recognized Italy’s definitive ownership of the Dodecanese Islands and Kastellorizo, but it did not provide for the self-determination of the inhabitants of these islands in the future.

Military Construction

The treaty confirmed Italy’s sovereignty over the Dodecanese, with Leros, due to its strategic position in the eastern Mediterranean and the geomorphology of its coasts, becoming the ideal choice for the creation of a state-of-the-art aero-naval base.

The Lakki Bay, with the largest natural deep-water port in the Mediterranean, was deemed the most suitable for this purpose, and the first works to establish the base began in May 1923, just before the signing of the Treaty of Lausanne.

The Naval Base was developed at the Gonia site in accordance to the decree of September 4, 1925 , and the barracks were built in 1930. In 1935, the hospital building was erected, while a year earlier, the area was included in the urban plan, with the roads of the base being integrated into the road network of the newly established town.

At the site where the villa of Cigadas Pasha stands in Lepida, the first seaplane station was created, which in 1924 was decided to be developed into an aero-naval base consisting of hangars for the cover and maintenance of seaplanes (with two cranes for launching them into the sea), warehouses and offices.

The base reached its final form in 1925 when its headquarters and the impressive barracks, with the characteristic large field in front of them, were built. The Cigadas Pasha villa hosted the Officers’ Club of the base, as well as a series of residences with single-story and two-story houses in a particularly well-maintained environment around it, for the accommodation of officers, non-commissioned officers, and their families.

The base was named after the young lieutenant Gianni Rossetti, a pilot of the Royal Italian Navy, who crashed into the bay with his seaplane on March 29, 1924.
From 1926 to 1929, the base expanded to Saint George with the construction of a 95-meter-long pier and the creation of a new Naval Base. There, next to the warehouses and the workshops of the shipyard zone, the rest of the pier was completed in 1935. A new barrack was added, along with new residences for the officers and sailors of the submarines, and facilities for fuel tanks and storage were created.
Opposite the Naval Base, the ammunition warehouses of Merikia were established, completing the defensive fortification of the island with the Porto Rina complex at Partheni and the Kamara warehouses.
The 24 long-range naval artillery batteries with 102 guns of various calibers and the 14 Anti-aircraft Gun Stations with a firepower of 49 machine guns were strategically placed on every height of the island, completing its defense.

The New Town of Portolago

The complete militarization of the southern part of the island and the ever-increasing needs for housing spaces and infrastructure for the families of officers at all levels, led to the creation of a new town, Portolago (modern-day Lakki).

In the early 1930s, the Portolago area had a small number of scattered buildings, mainly clustered along the coast. The Italian government, having recognized the military significance of the bay early on, had proceeded with the construction of the coastal road, which was necessary for the communication between the various military bases around the bay. Expropriation procedures in the area had already begun since 1928, along with the draining of the swampy and marshy land of Lakki.

In 1932, an inspection of the bay was conducted by Governor Mario Lago and his technical staff, after which the establishment of an autonomous municipality and an immediate intervention plan were decided.

The needs of the military base significantly influenced the town’s organization. The guiding principle of the urban plan was the creation of a center where all the essential functions for the community’s life (administration, services, commerce, culture) would be concentrated, reserving peripheral areas for the development of residential zones. The main feature of the constructions, which form an interesting ensemble of rational architecture, is the stylistic homogeneity that seems to harmonize the entire urban core, impressing with its aesthetic and constructional result even today.

The Anti-submarine Net

On the eve of World War II, Leros had been transformed into a peculiar unsinkable aircraft carrier for the Kingdom of Italy. It essentially served as Rome’s “flagship” in the region, in its attempt to gain control over the Mediterranean.

The entrance to the Lakki Bay, about 400m wide, formed by Cape Agistros and the steep descent of Patella, Katsouni, had become one of the most well-guarded naval targets in the area.
A key security measure was the anti-submarine net, which effectively sealed the bay’s entrance.

It was installed across the entrance, making access impenetrable to any external enemy.

Interlocking steel rings, combined with a lifting mechanism at the northern edge of the bay, operated with pulleys, cables, and floats to deploy the net, were responsible for the entry and exit of vessels from the naval base and the protection of the naval dockyard.

Today, the anti-submarine net lies on the seabed, forming an amorphous metal mass stretching along the bay, fully integrated into the marine ecosystem of the area.
We observe it from a depth of 14m down to 55m, which is the deepest point of the bay. Giant and smaller floats, which once supported this massive anti-submarine defense system, still impress today with their size and volume. Remnants of anti-submarine mines complete the eerie image of a not-so-distant grim period.

A small sample of it, along with other significant wartime materials, is presented as a permanent exhibit at the unique and evocative exhibition space of the War Museum of the Merikia Tunnel in Leros, serving as a silent witness to historical memory.

Acknowledgments

On October 30, 2021, in the Leros Dive Project that we conducted on the island of Leros, we dived in this unique spot, a witness to the unique defensive armouring of the island in a historically turbulent time.
We would like to thank the Hydrovius Diving Center and in particular, its owner Kostas Kouvas and his son Tasos for the excellent cooperation we had throughout our expedition, as well as for the valuable knowledge they passed on to us.

In these dives took part: Akis Seasidis, Christos Michail, Ventouris Bountouris, Vassilis Tsiairis, Nikolas Margaritis, and Andreas Andrikopοulos.

Historical research and content writing: Andreas Andrikopοulos.