lifeboat

剑桥词典

a large boat that is kept ready to go out and save people who are in danger in the water
（用于救援生命有危险的人的）救生船，救生筏

a small boat kept on a ship for people to leave in if the ship is not safe or might sink
（配在船上供逃生用的）救生船，救生筏 返回 lifeboat