Which piece of equipment is used to assist with safe landings in water?

The life raft is specifically designed to aid in safe landings on water by providing a floatation device that can be deployed during emergencies. In the event of a water landing, the life raft can be inflated and used to help crew members and passengers remain safe and buoyant until rescue can be arranged. It is an essential piece of safety equipment, particularly for aircraft operating over large bodies of water.

The other choices do not serve the purpose of facilitating safe water landings. A ballistic vest is intended to provide protection against small arms fire and does not offer any floatation capability. An oxygen cylinder is used for providing supplemental oxygen at high altitudes and does not contribute to water safety. A flight suit is designed to protect pilots in various flying conditions but does not aid in landing on water. Therefore, the life raft is the only option that directly addresses the need for safety in water landings.