WaveDepth: Water Depth

WaveDepth estimates how deep the water is by watching what waves do as they cross it. In deep water a wave barely feels the bottom. As the seabed rises the wave slows, its crests bunch together, and it grows taller — wave shoaling. How much taller depends only on the depth and the wave period, so measuring that change at several points along the wave's path recovers the depth at each one. All you need is one brightly coloured floating ball and a steady place to rest your phone. HOW A MEASUREMENT WORKS 1. Register your ball. Circle it once in a photo and enter its real diameter. That single number sets the scale for everything that follows. 2. Film the water. Up to two and a half minutes, split into five 25-second sections with a five-second gap between them. Move the ball to a new spot during each gap. 3. Mark the ball in each section. You get one frame per section — circle the ball on each. That fixes its size and colour for tracking that stretch of water. 4. Read the depth. The app follows the ball twenty times a second, measures the wave period from both the ball's motion and the water around it, and reports a depth for every section. WHAT YOU SEE Every section gets its own card: the depth, the camera-to-ball range, the wave amplitude and how it compares with the reference section, the period used, the ball's width in pixels, the scale at the ball, and the phone's tilt. Open the diagnostics on any section for the frames analysed, the detection rate, the tracking confidence, the drift removed by the fit, and any period estimates that were measured but deliberately left out of the calculation. Nothing is hidden behind a summary. If a number looks wrong, the numbers behind it are there too. ALREADY HAVE MEASUREMENTS? Manual mode takes a wave period and a set of amplitudes and returns the depth profile directly, with no filming required. ON YOUR DEVICE All video analysis runs on your iPhone. Nothing is uploaded, no account is needed, and the app makes no network requests of its own. Available in English, Spanish, French, Portuguese, Japanese, Korean and Simplified Chinese. PLEASE READ These depth readings are rough estimates and can be inaccurate. Do not rely on them for navigation, safety, or any real-world decision. WaveDepth is a tool for curiosity and experiment — it is not a depth sounder and not a charting instrument. The developer accepts no responsibility for any use of these results.