The present disclosure relates to a system for determining a location of an in-water object. The system includes a first wearable device and at least three sensors. Each sensor is placed in water, and is configured to emit an electrical signal. The first wearable device is located on a to-be-located object, the to-be-located object is placed in the water, and the first wearable device is configured to: separately determine received signal strength indicator RSSI values of received electrical signals emitted by the at least three sensors, determine a distance between the first wearable device and each sensor according to the determined RSSI value, determine a location of the first wearable device in the water according to a pre-measured location of each sensor and the determined distance between the first wearable device and each sensor, and use the location as a location of the to-be-located object in the water.