Each year on 3 September, Australia observes Merchant Navy Day, honouring the men and, in some cases, women who served in the Merchant Navy carrying troops, fuel, food and munitions, frequently on unarmed or lightly armed vessels.

The date marks the anniversary of the sinking of the passenger liner SS Athenia in 1939, torpedoed within hours of Britain's declaration of war and the first Allied ship lost in the Second World War.

The Merchant Navy's contribution is often overshadowed by that of the armed services, yet the risks faced by merchant seamen were severe.

The Australian War Memorial estimates more than 800 Australian merchant mariners died serving the Allied cause across both world wars, and the wartime fatality rate among Seamen's Union of Australia members reached 8.5 per cent, a higher proportion than that recorded across Australia's armed services.

While the exact number of Australians who served in the Merchant Navy across the two world wars can't be confirmed, it is believed to be several thousand.

The Department of Veterans' Affairs' WW2 Nominal Roll alone lists about 3,500 merchant mariners, though this is understood to be an undercount, and the Seamen's Union of Australia had roughly 4,500 members at the outbreak of that war.

No reliable equivalent estimate exists for the First World War.

The Department of Veterans' Affairs' World War Two Nominal Roll records two Boorowa-born men who served in the Merchant Navy during the war.

Noel Edward Delaney was born in Boorowa in 1924.

He engaged for service on 10 January 1942, at just 17 years of age, signing on at Sydney while living at Waverton.

He served as an able seaman, and his last recorded engagement, on 23 December 1943, was aboard the ship Penican.

Noel William Sligar was born in Boorowa in 1927.

He engaged for service on 2 February 1944, signing on at Brisbane.

He served as an ordinary seaman, and his final engagement, on 7 September 1945, just after the war's end, was aboard the SS Henry H Sibley, an American-built Liberty ship.

Australian merchant seamen frequently crewed Allied vessels of all nationalities, not only Australian-flagged ships, and Sligar's service reflects this.

The surname Sligar appears several times on Boorowa's World War Two honour roll, suggesting he was part of a well-known local family.

Neither Delaney nor Sligar is known to have lost his life in service, and so neither is among the 862 names — 184 from the First World War, 678 from the Second — honoured on the bronze plaques of the National Merchant Navy War Memorial in Kings Park, Canberra, which specifically commemorates mariners who sailed under the Red Ensign and did not return.

Their service is nonetheless part of the same story: the memorial stands for the whole of the merchant service's wartime contribution, of which men like Delaney and Sligar, who survived their engagements, were as much a part as those who did not.

The Red Ensign itself carries its own protocol.

It is generally reserved for use at sea, flown by Australian-registered merchant ships, but may also be flown on land for ceremonial occasions.

Merchant Navy Day, 3 September, is the day on which Australians are specifically encouraged to fly it, subordinate to the Australian National Flag, in recognition of the merchant service's contribution.

If you have further information on Noel Delaney, Noel Sligar, or any other Boorowa-area merchant mariner, the Boorowa News would welcome hearing from you.