I recently came across NOAA’s bathymetric data viewer https://maps.ngdc.noaa.gov/viewers/bathymetry/ and thought I’d share a tutorial on some of the things I’ve learned from it. To start with, free access to this data from NOAA is awesome. Ships, and in some cases planes, spent weeks or even months compiling each survey and to have it here at our fingertips is an amazing resource for anyone who likes finding new fishing and diving spots. While it has its limitations and coverage only extends to certain areas, in the areas where high resolution bathymetric imagery exists, it is a great tool.
When you first visit NOAA’s bathymetric data viewer found at this link https://maps.ngdc.noaa.gov/viewers/bathymetry/ you’re greeted by a rather confusing map of green lines, each representing a survey that has been performed. What we’re mainly interested in is the creme de la creme of surveys, the Bathymetric Attributed Grid (BAG) Color Shaded Relief Imagery (picture 2). These are very high resolution surveys of the ocean floor that show just about everything on the sea floor from rocks to shipwrecks to old pilings. Once you’ve selected BAG Color Shaded Relief Imagery you can zoom in to areas that interest you. Unfortunately there isn’t a ton of coverage for this type of survey simply because they’re expensive to undertake and it’s a big ocean. If you’re lucky like those of us in South Florida and the Keys there’s an area near you that you can check out for potential spots (California has a lot of high quality coverage as well). And even if there isn’t anything near you, new surveys are continuously added.
Since there are a lot of features to this, I’ll keep this brief by leaving you with one tip I’ve found useful. You can overlay NOAA Raster Navigational Charts over the BAG imagery by selecting it from the "options" menu in the top right corner of the page (picture 3). What this means is that all those spots on your traditional charts that say rocky or wreck that you’ve always wondered if there was anything actually there, well it’s easy to zoom in on some of those spots and see what the high resolution imagery is showing there. Is there always something? No, but a lot of times there is.
Where this data excels is at helping anglers and divers find spots that are off the beaten path so to speak. In areas with a lot of pressure most wrecks, reefs, and rock piles are well known. What high resolution bathymetric imagery is great at though is pinpointing individual rocks, wrecks, or debris fields that are on an otherwise flat bottom. This site has a lot of features and if you like finding new spots to fish or dive, it’s worth taking some time to explore the areas you usually boat. Play around with some of the other survey types too and if you find something cool check it out on your next trip.
I’ve included a few pictures of wrecks and reefs I’ve found that don’t show up on the chart that look promising.