Question: What is the nationality of the ship when the principle victims are Civilians?
SQL: SELECT "Nat." FROM "2-13046272-2" WHERE "Principal victims" = 'Civilians';

Question: what is the name of the Battleship with the battle listed on May 13, 1915?
SQL: SELECT "Name" FROM "2-13046272-2" WHERE "Ship Type" = 'Battleship' AND "Date" = 'May 13, 1915';