Greater amberjack fishing out of Marathon happens in 60-200 ft of water, past the reef line, on Gulf Stream structure. This page is written for skippers running their own boat. It covers when to go, how far and how deep boats run, which named grounds fall inside the depth band and which don’t, who fishes for them locally, and where the rules live. For the wider coast, see the greater amberjack fishing in the Atlantic Southeast and the Atlantic Southeast offshore fishing guide.
Season
Biology and range are covered in our greater amberjack guide. This page sticks to Marathon.
Memory Maker, a Marathon charter, puts the best action spring through fall. That is the only season window we give.
Where boats run
Boats leave the Middle Keys, cross the reef line, and fish the structure beyond it. The depth band below is the filter for every ground on this page.
Past the reef line
Boats run offshore past the reef line onto Gulf Stream structure. The port page on running out of Marathon covers ramps, channels, and where to read conditions. Before you go, check the NWS Key West marine forecast for wind, wave height, and period from the official source.
Depth band
Memory Maker finds greater amberjack in 60-200 ft, with about 60 ft as the shallow edge. The 60 and 200 ft lines on Chart Contours mark the band. Chart layers are not for navigation. Measure each ground below against that band.
Grounds and structure
Six named grounds sit near Marathon, sorted here by depth against the 60-200 ft band.
| Ground | Depth (ft) | Structure | In 60-200 ft band? |
|---|---|---|---|
| Seven Mile Bridge Reef | 90 | Bridge spans and concrete | Yes |
| Marathon Reef Site | 100 | Bridge rubble | Yes |
| Thunderbolt | 120 | Named structure, 4 mi south of Marathon and Key Colony Beach | Yes |
| Long Key Reefs | 24-26 | Bridge spans and concrete | No, shallower |
| Marathon Hump (Marathon West Hump) | 480 (shallowest point) | Deep hump | No, deeper |
| 409 Hump (also listed as 408 Hump) | Not listed | Hump, top Middle Keys blackfin tuna spot | Not an amberjack depth |
The bridge-rubble reefs and the Thunderbolt also hold other reef fish. The reef fish guides cover the regional and species-group picture.
Inside the band
Three grounds fall inside 60-200 ft, listed here from shallowest to deepest.
- Seven Mile Bridge Reef, 90 ft. Bridge spans and concrete.
- Marathon Reef Site, 100 ft. Bridge rubble.
- Thunderbolt, 120 ft. It sits 4 mi south of Marathon and Key Colony Beach.
Deep humps and shallow spans
Long Key Reefs are bridge spans and concrete at 24 and 26 ft, shallower than the band.
Marathon Hump (Marathon West Hump) has a shallowest point of 480 ft. 409 Hump (also listed as 408 Hump) is named as a top Middle Keys blackfin tuna spot. Mark both as Middle Keys landmarks, but don’t plan amberjack drops on them, since their tops sit far below 200 ft.
How it’s fished and who fishes for them
The local pattern combines the run past the reef line, the 60-200 ft band, and named structure. Build your day around those three.
Memory Maker Sportfishing
Memory Maker Sportfishing lists greater amberjack. It runs a 29-ft SeaVee center console, a restored 2000 model, and the captain is Jon Henry. Details are on the Memory Maker Guidesly listing.
FAQ: greater amberjack fishing out of Marathon
When is the best time for greater amberjack out of Marathon?
Spring through fall, according to Memory Maker, a Marathon charter.
How deep do you fish for them?
60-200 ft, past the reef line. About 60 ft is the shallow edge of the band.
Is the Thunderbolt in the amberjack depth range?
Yes. It sits at 120 ft, 4 mi south of Marathon and Key Colony Beach, inside the band.
Do the humps hold them?
Marathon Hump’s shallowest point is 480 ft, outside the band. 409 Hump is known as a blackfin tuna spot. Fish for amberjack on 60-200 ft structure.
Where are the rules?
FWC sets the state rules. Check the Florida regulations page before fishing.
