The monument is dedicated to the memory of the American servicemen who were lost when the troopships the Tuscania was torpedoed by a German U-boat in the North Channel and the Otranto which sank following a colliion with another convoy ship in a storm off the west coast of Islay.
See http://freepages.history.rootsweb.ancestry.com/~carmita/hoyle/Red_Cross.htm
and http://raycityhistory.wordpress.com/2010/10/12/oct-12-1918-372-u-s-soldiers-lost-in-sinking-of-otranto/