When and where boats run out of Marathon
Infinite Blue Charters says, "Peak season runs fall through spring here in the Keys." Plan trips inside that window, and use the Atlantic Southeast blackfin guide (see also the Atlantic Southeast fishing guide) for the wider regional timing picture.
Blackfin tuna fishing out of Marathon centers on the Marathon Hump seamount, which Southern Sons lists about 15 miles offshore. Closer structure sits well inside it, and Thunderbolt is the nearest named option. If you are running out of Marathon for the first time, the Marathon port guide covers the port’s water, channels and launch details.
Before you leave the dock, read the NWS Key West marine forecast and check the Sombrero Key buoy observations. Use those official numbers to decide whether your boat goes out.
Run planning comes down to three points:
- Season: fall through spring is the peak window in the Middle Keys.
- Main run: Marathon Hump, about 15 miles offshore.
- Close option: Thunderbolt, 4 miles south of Marathon and Key Colony Beach.
Grounds and structure off Marathon
These are the named structures boats use from this port, with depths in feet.
| Name | Depth (ft) | Note |
|---|---|---|
| Marathon Hump (Marathon West Hump) | 480 (shallowest point) | Seamount, about 15 miles offshore per Southern Sons |
| 409 Hump (also listed as 408 Hump) | – | A top Middle Keys blackfin spot |
| Thunderbolt | 120 | 4 miles south of Marathon and Key Colony Beach |
| Seven Mile Bridge Reef | 90 | Bridge spans and concrete |
| Marathon Reef Site | 100 | Bridge rubble |
| Long Key Reefs | 24 and 26 | Bridge spans and concrete |
The Marathon Hump
The Hump is a seamount, also called the Marathon West Hump, with a shallowest point of 480 ft. Local boats work their baits around 200 ft, well above that, so the fishing happens in the water column over the Hump and not on its top.
The 409 Hump
The 409 Hump, also listed as 408 Hump, is named as a top Middle Keys blackfin spot. The two numbers refer to the same mark.
Thunderbolt
Thunderbolt sits in 120 ft, 4 miles south of Marathon and Key Colony Beach. The Hump is about 15 miles out, so Thunderbolt is the shorter run and the practical choice when you want less time and fuel between the dock and the first drop.
Bridge reefs: Seven Mile, Marathon Reef Site, Long Key
Three more named structures sit near the port. Seven Mile Bridge Reef is bridge spans and concrete at 90 ft. Marathon Reef Site is bridge rubble at 100 ft. Long Key Reefs are bridge spans and concrete at 24 and 26 ft. Use them as named reference structure near Marathon. Chart Contours shows the contours around them in the app, though chart layers are not for navigation.
How blackfin are fished out of Marathon
Local boats work baits and jigs around 200 ft. For general behavior and tackle, see the blackfin tuna species guide.
The local methods, in the order most boats use them:
- Deep live-baiting with pilchards, blue runners and herring on two rods
- Trolling small feathers and swimming plugs
- Flutter jigging over marks
- Live chumming to bring fish up
Deep live-baiting on two rods
Pilchards, blue runners and herring are the live baits used locally. Fish them deep on two rods in the water column around 200 ft, which keeps two baits working at once.
Trolling small feathers and swimming plugs
Trolling small feathers and swimming plugs covers water between marks and keeps lines out while you watch the sounder for fish.
Flutter jigging over marks
When the sounder shows fish, drop a flutter jig on the marks and work it in the same water column, around 200 ft, where the live baits are fished.
Live chumming
Live chumming pulls fish up toward the deep live baits and the jigs. Set your baits first, then chum to bring the school into reach. None of this guarantees fish. It is an order of operations for the water you are over.
Who fishes for blackfin out of Marathon
These operators list blackfin tuna out of Marathon:
- Always Late Fishing Charters: Always Late, a 32-ft SeaVee center console, 6 passengers, Capt. Lucas Ponzoa.
- Infinite Blue Charters: Happy Ours II, a 47-ft Sea Ray, and a Wellcraft 290 Coastal, Capt. Robert Williams.
- Southern Sons Charters: Capt. Josh Cox.
- Big Game Sportfishing Charters: a 35-ft center console, Capt. Ariel Medero.
Tom Thumb Marathon Offshore Bull & Cow Dolphin Tournament
The Tom Thumb Marathon Offshore Bull & Cow Dolphin Tournament runs out of Marathon, usually in April. It is a dolphin event, not a blackfin event.
FAQ: blackfin tuna out of Marathon
How far is the Marathon Hump?
The Marathon Hump sits about 15 miles offshore, per Southern Sons Charters. Its shallowest point is 480 ft. Thunderbolt, 4 miles south of Marathon and Key Colony Beach, is the closer option for a shorter run.
When is blackfin season in Marathon?
Infinite Blue Charters says, "Peak season runs fall through spring here in the Keys." Time your trip to that window, then check the official forecast and buoy numbers before you commit to the run.
What depth do you fish?
Local boats work baits and jigs around 200 ft. The Hump’s top is 480 ft, so set your baits and jigs by the marks on your sounder, not by the Hump’s shallowest point.
Is the 409 Hump the same as the 408 Hump?
Yes, these are two names for the same spot. It is listed as 409 Hump, also listed as 408 Hump, and named as a top Middle Keys blackfin spot. Either number works when you talk to local boats.
Who runs charters for blackfin out of Marathon?
Four operators list the species. Always Late Fishing Charters runs Capt. Lucas Ponzoa. Infinite Blue Charters runs Capt. Robert Williams. Southern Sons Charters runs Capt. Josh Cox. Big Game Sportfishing Charters runs Capt. Ariel Medero.
Where can I read about other tunas?
The tuna fishing guides cover other tunas, with species and regional detail you can use alongside this page.
