The Irish Mercantile Marine during World War II continued essential overseas trade during the conflict, a period referred to as The Long Watch by Irish mariners. Irish merchant shipping saw to it that vital imports continued to arrive and exports, mainly food supplies to Great Britain, were delivered. Irish ships sailed unarmed and usually alone, identifying themselves as neutrals with bright lights and by painting the Irish tricolour and EIRE in large letters on their sides and decks. Nonetheless twenty percent of seamen serving in Irish ships perished, victims of a war not their own: attacked by both sides, though predominately by the Axis powers.[citation needed] Often, Allied convoys could not stop to pick up survivors, while Irish ships always answered SOS signals and stopped to rescu