What started as a 20 minute school assembly in tribute to two Merchant Navy veterans has become a four day celebration of the service.
Barra and Vatersay War Memorial lists 125 names
A school on Barra will host events in August and September to remember sailors from the islands who served or died during World War II.
Castlebay School head teacher David Bowman decided to organise the tributes after visiting a local war memorial.
The main event will be held on 3 September - Merchant Navy Day.
Castlebay on Barra will also stage activities on 31 August and on 1 and 2 September.
Events include flying the red ensign, screenings of vintage films such as San Demetrio, London - a ship on which Barra men served - and special services.
Pupils will also give presentations on their projects about the Merchant Navy.
Castlebay Community School is bi-lingual Gaelic/English for pupils aged three to 18 and comprises pre-school, primary and full six-year secondary classes.
Merchant Navy Day is held on 3 September, the date in 1939 when the SS Athenia was sunk by a u-boat on the first day of World War II
The vessel was torpedoed off the north-west coast of Ireland
The passenger ship had been built by Fairfields in Govan, Glasgow
Mr Bowman arranged the original school assembly after being shocked by the losses listed on the Barra and Vatersay War Memorial.
Almost all of them were Merchant Navy or Royal Navy personnel.
The head teacher said: "Barra's population has been just above the 1,000 mark for over a 100 years.
"The total of war dead one would expect from such a population would be of the order of three to six.
"In fact there are 125 names on the Barra and Vatersay War Memorial. There are a few soldiers and airmen named.
"However, 95% are Navy, of whom 75% are Merchant Navy."
He added: "This undertaking started as a modest 20 minute assembly to acknowledge two Benbecula Merchant Navy Association members.
"Although in their 70s they struggled four times to get to our Remembrance Service in November and were twice stuck on Eriskay unable to get across to Barra."
Asked for an alternative date to avoid foul winter weather, the men suggested national Merchant Navy Day.