Deadly ANZACs beneath the waves: Australia's forgotten WWI submarines

World War I, also known as the Great War, erupted in Europe in July 1914 and raged on until November 1918.

The central powers, including Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria, were arrayed against the Allies, comprising primarily the United Kingdom, France, Russia, Italy, and later the United States.

Each side was equipped with an extensive arsenal of weaponry and military technologies that were, at the time, considered cutting-edge.

Australia, as part of the British Empire, was naturally drawn into the conflict on the side of the Allies.

Despite its relatively isolated geopolitical isolation, Australia had a strong sense of duty to support the mother country in its time of need.

With a population of fewer than five million people, Australia's contribution to the war effort was remarkably significant.

Over 400,000 Australians enlisted to fight for Britain.

Prior to World War I, Australia's naval power was still in its formative stages. The island continent, being a part of the British Empire, had relied heavily on the Royal Navy for its maritime defence.

However, the years leading up to WWI saw a shift in this paradigm. With the increasing tensions among global powers and the emerging understanding of Australia's strategic importance, there was a growing recognition that Australia needed to bolster its own naval capabilities.

This culminated in the establishment of the Royal Australian Navy (RAN) in 1911, which replaced the former colonial naval forces.

The RAN was a significant milestone for Australia. It was an important step in its emerging sense of national identity and sovereignty.

Initially, the RAN consisted of a small but capable fleet, including the battlecruiser HMAS Australia, as well as some light cruisers, and destroyers.

They were initially intended to cooperate with the Royal Navy in maintaining security in the Pacific region.

The most groundbreaking addition to the RAN, however, was the inclusion of two E-class submarines, HMAS AE1 and AE2, purchased from Britain.

This was a visionary move, considering the fact that submarines were a relatively new addition to naval warfare.

These submarines, part of the British E-class, were commissioned in 1914. They were approximately 55 metres long, with a displacement of about 800 tons when submerged.

They were powered by diesel engines and electric motors, which meant that they were capable of operating on the surface as well as underwater.

Armed with torpedoes, they were designed for stealth and surprise attacks on enemy vessels.

However, operating these submarines was still a very difficult task. Submarine warfare was a very new concept, and few men had the training or experience required to manage these complex machines effectively.

Specifically, the crews of AE1 and AE2 were primarily made up of British Royal Navy personnel, with a small number of Australians included.

It was decided that the operational base for the submarines should be located at Garden Island in Sydney.

From this naval hub, the submarines would then embark on their war missions that were considered critical to the region.

The AE2 was sent on one of its first missions in the Dardanelles in 1915 as part of the Gallipoli Campaign.

The Dardanelles was a narrow strait connecting the Aegean Sea to the Sea of Marmara in present-day Turkey.

It was a strategically crucial point held by the Ottoman Empire, an ally of the Central Powers.

Penetrating the strait was risky due to its heavy fortification and the strong currents.

Nevertheless, the AE2, under the command of Lieutenant Commander Henry Stoker, was ordered to "run amok" in the Sea of Marmara to divert the Ottoman forces.

On the night of April 25, 1915, coinciding with the landing of Australian and New Zealand forces on the Gallipoli Peninsula, the AE2 undertook its mission.

It successfully navigated through the dangerous waters, evading mines, enemy patrol boats, and strong currents.

The AE2's incursion was the first successful Allied submarine operation in the Dardanelles and it brought a much-needed morale boost to the beleaguered troops.

Over the next few days, the AE2 continued its disruptive operations in the Sea of Marmara, torpedoing enemy vessels and keeping the Ottoman forces on high alert.

Unfortunately, on the 30th of April, the AE2 was hit by the Ottoman torpedo boat Sultanhisar.

Unable to dive due to damage, Stoker gave the order to scuttle the submarine to prevent it from falling into enemy hands.

The crew was captured and spent the remainder of the war as prisoners.

The other Australian submarine, the AE1 was sent to the waters off German New Guinea as part of the Australian Naval and Military Expeditionary Force.

On September 14, 1914, while on patrol off the Duke of York Islands near Rabaul, the AE1, commanded by Lieutenant Commander Thomas Besant, mysteriously vanished.

It was last seen from the nearby Australian ship HMAS Parramatta. After the AE1 failed to return to harbour, a search was initiated.

Despite extensive efforts, no trace of the submarine or its 35 crew members, comprising both Australians and British, was found.

Over the years, several attempts were made to locate the lost submarine. The Australian government, navy, and numerous private expeditions invested significant resources into solving the mystery of AE1.

It wasn't until 2017, more than a century after the submarine's disappearance, that an expedition led by Find AE1 Ltd, and funded by the Australian government, was finally successful.

The wreck of the AE1 was found near the Duke of York Islands, in nearly 300 meters of water, largely intact.

However, the wreck showed signs of a catastrophic event that led to its sinking.

The most common assumption is that it was caused by an onboard explosion.

The precise cause of the submarine's sinking, however, remains unknown.

In the wake of the loss of both the AE1 and the AE2, the Royal Australian Navy remained without any submarines.

It wouldn't possess any more until the 1920s, with the J-class submarines transferred from the Royal Navy.

While the war continued for several more years, Australia's focus shifted more towards its contributions to the land campaigns on the Western Front and in the Middle East, as well as maintaining its naval surface fleet.