1N-COUNT (派往海上救助的)救生船 A lifeboat is a medium-sized boat that is sent out from a port or harbour in order to rescue people who are in danger at sea. (派往海上救助的)救生船
2N-COUNT (船上备用的)救生艇 A lifeboat is a small boat that is carried on a ship, which people on the ship use to escape when the ship is in danger of sinking. (船上备用的)救生艇
The captain ordered all passengers and crew into lifeboats.