Mobile Depth & Bottom Finder

I need a compact fish-finder solution that concentrates solely on showing real-time water depth and bottom shape. Instead of a built-in display, all readings must stream wirelessly to my phone or tablet, so the interface has to be touch-friendly on both iOS and Android. You are free to choose the underlying tech—Bluetooth or Wi-Fi, an off-the-shelf transducer or a custom sonar module—so long as the connection is reliable and the readings stay accurate while the boat is in motion. I’m open to Flutter, React Native, or fully native code; whichever lets you move fastest and keeps maintenance simple. Deliverables • Recommendation and sourcing links for the transducer and any required interface hardware • Mobile app that plots live depth data, scrolls a contour of the lake bottom, and switches between metres/feet • Basic calibration routine and on-water test video proving stable readings I’ll be available for quick feedback during development and can test early builds on the water. If this sounds like your kind of project, tell me how you would tackle the hardware selection and app architecture, plus a rough timeline for hitting the water with a working prototype.