<Li> USS Shawmut (former Eastern steamship Massachusetts carried 320 mines on one deck) </Li> <Li> USS Canandaigua (former Southern Pacific freighter El Siglo carried 830 mines on 3 decks) </Li> <Li> USS Roanoke (former Southern Pacific freighter El Dia carried 830 mines on 3 decks) </Li> <Li> USS Canonicus (former Southern Pacific freighter El Cid carried 830 mines on 3 decks) </Li>

When did great britain and germany plant mines in the north sea