Wireless sonar sensor for fish finders that provides depth information up to 45 m. 90 degree beam angle and 125 kHz sonar frequency for broad coverage in mid depth ranges. Durable plastic housing with a watertight seal cover and a seal ring to protect electronics in wet conditions. Powered by a replaceable CR2032 battery for easy field replacements. Designed to work with compatible fish finder systems that support wireless sonar sensors. Compact plastic construction allows flexible mounting on boats, kayaks, or shore setups. Quick and cable deployment, making it suitable as a supplementary sensor or replacement for damaged transducers. Practical use scenarios: 1) On a small boat or kayak, mount the sensor to scan the water column and identify fishholding structures within 45 m depth. 2) From a dock or pier, extend sonar coverage to shoreadjacent depths, useful for locating fish around pilings or dropoffs. 3) On temporary or rental setups, move the sensor between vessels to test or verify depth readings without rewiring.