A sonar fish finding system includes at least one sonar device which attaches to a fishing line and floats on the water like a fishing bubble, float, or bobber. The at least one sonar device pairs with a wireless computing device over a Bluetooth connection to provide information to a fisherman about what is under the surface of the water proximal to the at least one sonar device. Processing may be performed incrementally on subsets of sonar data samples in order to allow for a complete result without requiring storage of the entire set of data samples at once. The at least one sonar device is configured to send the sonar data samples to a remote computing system either directly or indirectly through a wireless computing device. Based on the received sonar data samples, the remote computing system may send the wireless computing device information about both real-time fishing hotspots, and predicted fishing hotspots based on historical data and current conditions.