UTERTo find wrecks, reefs and humps to fish, start with public data: NOAA's nautical charts mark charted wrecks and obstructions, coastal states publish their artificial reef sites with coordinates, and NOAA's bathymetry shows the humps and ledges as tight depth contours. Then confirm the structure on your sounder before you drop a bait, because published numbers get you close, not on top.
You don't need a captain's private list to fish good structure. This guide covers where each kind of public data comes from, how to read a depth map for humps and ledges, how to tell whether a mark is worth the run, and how to fish it once you're there.
The four kinds of offshore structure
| Structure | What it is | Where the data comes from | Typical fish |
|---|---|---|---|
| Wrecks | Sunken ships, barges, aircraft and debris | NOAA charts (ENC), state reef programs for intentionally sunk vessels | Amberjack, red snapper, gag, tautog up north |
| Artificial reefs | Concrete modules, culverts, bridge rubble, ships placed on purpose | State and county artificial reef programs | Snapper, grouper, black sea bass, triggerfish, sheepshead |
| Natural reef and hard bottom | Coral, rock and live bottom | Charts (rock and coral bottom), state habitat maps | Vermilion, red grouper, porgies |
| Humps and ledges | Rises and steps in the sea floor | NOAA bathymetry (depth grids and contours) | Blackfin, amberjack, grouper, pelagics over the top |
Where to find wreck locations
NOAA nautical charts
NOAA's electronic navigational charts (ENCs) mark charted wrecks, obstructions and rocks. You can see them on any chart plotter or chart app, and NOAA's ENC Direct to GIS lets you export the features in GIS formats.
You may also find old lists from NOAA's AWOIS wreck database online. NOAA's Office of Coast Survey says AWOIS has been retired and is no longer updated, and points people to ENC Direct instead. Treat old AWOIS numbers with care.
What a chart wreck symbol tells you (and doesn't)
- Charts are made for safe navigation. A wreck is charted because it matters to a boat, not because it holds fish.
- Some charted wrecks are dangerous, shallow hazards close to shore; others are deep and harmless. The chart shows which with its symbol and depth.
- Positions can be approximate, especially for old records. Plan to search around the mark.
Where to find artificial reef locations
Most coastal states run an artificial reef program and publish the sites. A few to start with:
- Florida: FWC's Locate an Artificial Reef page (map, spreadsheet and GIS files), plus county lists. See our Florida artificial reef guide.
- Texas: TPWD's artificial reef program.
- Alabama: Outdoor Alabama's artificial reefs, one of the busiest reef zones on the Gulf.
- South Carolina: SCDNR's marine artificial reef program.
- New Jersey: NJ Fish and Wildlife's reef program.
Other states, including North Carolina, Georgia, Mississippi, Louisiana and New York, have programs too. Search "[state] artificial reef program" for the official page.
How to find humps and ledges on a depth map
Humps and ledges don't show as symbols. You find them by reading the contours. NOAA's National Centers for Environmental Information publish bathymetry like the U.S. Coastal Relief Model, which is what most depth shading on fishing maps is built from.
Reading the contours
- A hump is a ring or a set of rings of contour lines with shallower water inside, surrounded by deeper water. The tighter the rings, the steeper the sides.
- A ledge is where contour lines crowd together in a line: the bottom steps down quickly. Ledges often run parallel to the coast.
- A drop-off or shelf edge is a long band of crowded contours where the bottom falls into deep water. Pelagics hunt along it.
- A point or finger is where contours bulge out toward deep water. Current wraps around points, and fish gather on the up-current side.
Why resolution matters
A depth grid can only show features bigger than its cells. Small ledges a few feet high, or a single wreck, can be invisible on a coarse map. That's why a sounder is still the final word: it shows what's directly under you, at full detail.
Is the mark worth the run?
- Relief: more height off the bottom usually means more fish. A ledge with a few feet of relief can be good; a hump that rises hundreds of feet is a fish magnet.
- Depth for the target: a reef in 30 ft holds different fish than one in 120 ft. Match the mark to the fish and the season.
- Current: structure with current running over it fishes better. Fish the up-current side.
- Pressure: a famous public reef close to the inlet gets fished hard. The less obvious marks nearby often hold more.
- Rules: some structure sits inside closed areas, marine reserves or special management zones with their own gear rules. Check before you fish.
Fishing structure once you find it
- Idle over the mark first and watch the sounder: find the structure itself, the fish on it and which way the current is going.
- Mark the high point and the fish, not just the published number.
- Anchor or drift up-current so your baits fall onto the structure, not past it. On deep humps, a controlled drift is often easier than anchoring.
- Fish the right level: grouper and snapper near the bottom, amberjack and pelagics higher up and over the top.
- Move if it's dead. Five or ten minutes without a bite on a good mark usually means try the next one.
Wrecks, reefs and humps in Fish Scouter
We built Fish Scouter's map so you don't have to download spreadsheets and type numbers into a plotter. Here's what's in it today:
- NOAA-charted wrecks, obstructions and rocks from the ENCs, along every US coast we cover.
- State artificial reefs and fish attractors from the state and county programs we've imported, starting with Florida's full FWC list and county reef lists.
- Depth shading and 3 ft contours from NOAA bathymetry, so humps and ledges show on the map. Not for navigation.
- Ledges and humps we read from the depth grid in the Gulf and the Florida Keys, each labeled with its relief and depth, and trolling marks along the Keys' 120 ft and 250 ft edges.
- A Structure filter that shows reefs, wrecks, ledges, hard bottom and jetties near you, on satellite, chart or street maps.
Tap any mark for the fish there this month and whether the next seven days suit it. Save it to My Spots (private by default, or shared with your clan), and on Captain or Guide export your spots as GPX for your plotter. See moving spots between Navionics, Garmin and Lowrance and our fish finder how-to pages. On the Guide plan, Take me there points you to a mark with a live arrow.
For more on the map side, read how to find fishing spots on a map. For Keys offshore structure specifically, see Florida Keys offshore fishing. The Panhandle red snapper, Mississippi Sound and Mobile Bay red snapper, Cape Fear gag and Jersey Shore tautog guides cover when structure fishing peaks on each coast.
Find your next mark
Wrecks, reefs, humps and ledges on one map, with the fish and the forecast for each. Try Fish Scouter free and find structure worth the run.