 In 1942 there was an increased U @-@ boat threat in the Caribbean against oil shipments . After Halifax and the UK started experiencing oil shortages , tanker convoys were organized between Caribbean ports and Halifax and New York City . In July , Fredericton was assigned to escort convoy <unk> / <unk> from Halifax to Aruba and back . Since the U.S. Navy had insufficient ships for these convoys , Fredericton along with six other Canadian corvettes was temporarily transferred to American naval operational command for convoy escort between Guantánamo Bay and New York City . She participated in these oil convoy escorts from September until February 1943 . 
