Depth
Bottom contour lines at nineteen fishing depths from 30 to 12,000 feet, each labelled. On the browser the numbers are always feet; the phone apps follow your depth-unit setting.
Static — does not update
More detail
How to turn it on. Depth is a button on the bar along the bottom of the map, on the iPhone app and the website. Tap it and black contour lines are drawn over whatever layer you have up. Tap it again to remove them. The button is off again each time you open the app.
The depths drawn are 30, 60, 90, 100, 150, 200, 300, 400, 500, 600, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 9000 and 12000 feet.
Reading the labels. On the website no unit is printed, so a line marked 600 is 600 feet, even if your depth unit is meters. On the iPhone app the unit is written on the line. The website draws every line at the same weight, so read the labels to tell the depths apart. More labels appear as you zoom in.
How to use it. Lines packed close together mean a steep bottom: a drop-off, a canyon wall, the shelf break. Lines far apart mean a flat bottom. Each cell of the survey behind them is about 1.2 nautical miles across, so a line can sit some way from where your sounder finds that depth, and a wreck or narrow ledge smaller than a cell never appears.
How it relates to the other bottom features. Seafloor Relief is the shaded picture of the bottom that is always under the map. It shows the shape and carries no numbers, and these lines put the numbers on it. The depth figure in the readout at the top of the map gives the depth at one spot. The Waypoints button marks cataloged structure such as rigs, wrecks and reefs.
Who makes it. RipIQ draws the lines itself, from a worldwide seafloor survey (GEBCO) with NOAA's more detailed coastal survey blended in over the US Gulf shelf.
Limits. The lines are the same at every date, time and depth setting, and they keep working when the live layers run late. The lines stop just short of the outer edge of the mapped water on purpose. To see what you must not use the app for, see Safety, limits and contacting us.
The numbers
| How often it updates | Never |
| How fresh it usually is | No delay |
| How detailed it is | About 1.2 nautical miles per cell |
| Where it covers | Everywhere the app maps; a thin band at the very outer edge is left blank on purpose |
| Observed or modeled | Observed: a worldwide seafloor survey, with NOAA's more detailed coastal survey blended in over the US Gulf shelf |
| What you see on screen | Black lines at 19 fixed depths from 30 ft to 12000 ft. Labels are feet with no unit printed on the website; feet or meters, with the unit, on the iPhone app |
Source: computed by RipIQ from GEBCO 2025 seafloor depth and the NOAA Coastal Relief Model.