Depth preview
Charted NOAA soundings for any patch of US water, pulled by your own browser. A preview of the desktop tool, not the whole of it.
Charted NOAA soundings for any patch of US water, pulled by your own browser. A preview of the desktop tool, not the whole of it.
Not for navigation. Estimates interpolated from charted data, in feet below mean lower low water. Verify against official NOAA charts before you go anywhere.
Draw a box on the water and this pulls the depth soundings NOAA has charted inside it, then fills the space between them so you can see the shape of the bottom. The arithmetic is the desktop tool’s, moved into the browser and checked against it cell by cell — the two agree exactly, or this would not be up.
It is a preview, and here is what that means. This page reads NOAA’s electronic charts and nothing else. The desktop version also pulls BlueTopo and USACE survey grids, merges every source shallowest-wins, applies the tide, draws the survey-confidence layer, and writes a GeoTIFF that ATAK will import. If the box you drew comes back thin, that is chart coverage, and the desktop tool would likely find more.
Everything runs on your machine. The chart data comes from NOAA and USACE directly to you. Where you are looking is never sent to me, because there is nothing here to send it to. This page is a static file; it has no server.
Depths are interpolated between soundings and the gaps can hide anything a surveyor did not sound. Surveys are often decades old. Nothing here knows about today's tide unless you ask for it, and nothing here knows about a wreck charted last week.