Redrockn and Rockin the Ship, the two fastest Thoroughbred qualifiers, will be challenged by six Quarter Horses in the Grade 3, $57,800 Catalina Derby over 870 yards at Los Alamitos on Saturday night. Redrockn has spent his two-race career at the 870-yard distance against Quarter Horses. He finished second in his career debut, then won his Catalina Derby trial by 3-1/2 lengths in 46.015 seconds for 870 yards.