A lifeboat is a special kind of boat that is designed to rescue sailors at sea. It must stay afloat in very rough seas. It is also designed to travel quickly, so it has very powerful motors.

The sides go very close to the water to make it easy for the lifeboat crew to haul people out of the water. The cabin is entirely enclosed and storm-proof. The hull has many compartments so that, even if one part of the hull hits a rock and takes on water, the other parts will stay water-free and allow the lifeboat to continue safely back to port.