Fathom turns your Garmin AMOLED display into a quiet explorer's instrument. The background is a generated nautical depth-contour chart -- deep navy field, hairline contour rings, and scattered depth soundings -- drawn in the same visual language Garmin built its reputation on: navigation. The time and date float over the center. Two complication callouts anchor in the lower quadrants, styled like entries in a chart legend. Nothing else. The chart is the identity. What you see at a glance: - Time (HH:MM) in dominant Space Mono numerals, centered over the chart's protected mid-field. - Date in your chosen format, immediately below the time. - Two user-selectable complication callouts in the lower-left and lower-right quadrants, each showing a label, a programmatic icon, and a live value. Two complication slots: Choose independently what each slot displays. Options are Steps, Heart Rate, Watch Battery, Body Battery, Calories, or None. The defaults (Steps and Battery) work on every device, cold on a first install, with no phone connection and no missing value. Set either slot to None and the chart shows through cleanly -- an intentional minimal state, not a placeholder. Accent color: Pick the color that tints the complication icons and callout hairlines. Four options: Chart Cyan (default), Amber, Sea Green, Paper White. The time and date contrast never change -- only the accent surface shifts. Date format options: Choose the format that matches how you think: Weekday (WED 19 JUN), Day-Month (19-06), Month-Day (06-19), or ISO week number (W25). Always-On Display: On supported AMOLED devices, Fathom switches to a burn-in-safe AOD state. The chart bitmap, date, and both complication callouts suppress entirely. A dim time remains, drifting within a safe pixel envelope each minute to protect the screen. The AOD screen turns black with all chart details and complications suppressed to save power and prevent burn-in. Battery discipline: Fathom redraws once per minute. There is no persistent animation, no seconds hand, and no per-second refresh. Body Battery reads from SensorHistory on a cached path, refreshed no more than once every five minutes, and never on the AOD draw path. The chart background is a static bitmap loaded once at layout, minimizing active draw calculations each minute for all-day wear. Device compatibility: Fathom runs on 46 round AMOLED Garmin devices across four resolution buckets: 454x454 (Venu 3, Forerunner 965, Forerunner 970, Fenix 8 47mm, Epix Pro 51mm), 416x416 (Forerunner 265, Venu 2, Epix 2, Fenix 8 43mm, Instinct 3 AMOLED 50mm), 390x390 (Vivoactive 5, Vivoactive 6, Venu, Forerunner 165, Instinct 3 AMOLED 45mm, Marq 2), and 360x360 (Forerunner 265S, Venu 2S). MIP/transflective devices, rectangular Venu variants, and MIP/grayscale Instinct products are not supported; the deep-navy chart and AOD polish require a full-color AMOLED display. Free to download and install on every compatible device you own.