Various implementations described herein are directed to a non-transitory computer readable medium having stored thereon computer-executable instructions which, when executed by a computer, may cause the computer to receive sonar data from a transducer after deployment of the transducer in a body of water. The computer may process the sonar data to detect a bottom of the body of water based on the sonar data received from the transducer. The computer may automatically trigger at least one event upon detecting the bottom of the body of water.