A system and a method are disclosed for enabling accurate estimation of a location of a water vessel. In an embodiment, a rescue system transmits a Short Message Service (SMS) message to a user device on the water vessel, the SMS message comprising a selectable option that, when selected, causes a location of the user device to be shared. Based on a selection by a user of the user device of the selectable option, the system receives a plurality of location coordinates from the user device at a plurality of respective times, each respective location coordinate describing a respective location of the user device at its respective time. The system computes an estimated location of the water vessel based on the plurality of location coordinates and an elapsed time between a current time and a time at which a last-received location coordinate was received. The system transmits the estimated location to a responder device.