When red grouper are here off Marathon
Red grouper fishing out of Marathon is shaped by a January-April closure that local operators work around, and by the cooler months, when fish move shallower. Marathon sits in the Middle Keys, and this guide covers the grouper water you can reach from your own boat: depth bands, named structure, the local method and the operators who run trips. Start on the 30-100 ft band and the 40-200 ft structure, with Thunderbolt at 120 ft as the named anchor. For the wider coast, see the red grouper fishing in the Atlantic Southeast and the wider Atlantic Southeast guide.
Ana Banana Fishing Company states that January-April is closed season. Infinite Blue Charters says fishing picks up in the cooler months, when fish move shallower, so the open cooler months are your shallow-water window. Life history and behavior are covered in our red grouper guide.
Local timing at a glance:
- Closed season: January-April, per Ana Banana Fishing Company
- Best fishing: cooler months, when fish move shallower, per Infinite Blue Charters
- Planning rule: check the state page before every trip
How far and how deep boats run out of Marathon
Two depth bands cover most of the grouper water out of Marathon. Ana Banana runs rocky areas and artificial reefs in 30-100 ft. Infinite Blue’s wreck and bottom trip works rocky bottom and structure in 40-200 ft. About 30 ft is the shallow end of the picture.
Thunderbolt, 4 miles south of Marathon and Key Colony Beach, is the only distance given here. Artificial reefs and bridge rubble make up the shallower band, and rocky bottom runs across the deeper one. In the cooler months, start on the 30-100 ft band and push to 40-200 ft structure from there.
| Band | Depth | What it covers | Run by |
|---|---|---|---|
| Shallow reference | About 30 ft | Shallow end of the range | n/a |
| Reef band | 30-100 ft | Rocky areas and artificial reefs | Ana Banana |
| Structure band | 40-200 ft | Rocky bottom and structure | Infinite Blue |
Grounds and structure that hold red grouper
The named marks below are listed in order of depth. For the artificial reef structure itself, own-boat anglers can start with FWC’s Florida Keys artificial reefs.
| Ground | Depth (ft) | Structure | Distance/location |
|---|---|---|---|
| Long Key Reefs | 24 and 26 | Bridge spans and concrete | Structure note only |
| Seven Mile Bridge Reef | 90 | Bridge spans and concrete | n/a |
| Marathon Reef Site | 100 | Bridge rubble | n/a |
| Thunderbolt | 120 | Structure | 4 mi S of Marathon/Key Colony Beach |
Long Key Reefs
Bridge spans and concrete at 24 and 26 ft. This is the shallow end, near the about 30 ft figure, and it suits the cooler-month move shallower.
Seven Mile Bridge Reef
Bridge spans and concrete at 90 ft, inside the 30-100 ft band.
Marathon Reef Site
Bridge rubble at 100 ft, at the deep edge of the 30-100 ft band.
Thunderbolt
120 ft, 4 miles south of Marathon and Key Colony Beach, in the 40-200 ft band.
Deeper marks you’ll hear about
Two deeper marks come up in Middle Keys talk. Both sit beyond the 200 ft edge of the listed red grouper range, so treat them as orientation marks rather than grouper spots.
- Marathon Hump (Marathon West Hump): shallowest point 480 ft.
- 409 Hump (also written 408 Hump): a top Middle Keys blackfin tuna spot.
How red grouper are fished from Marathon
The local method is bottom fishing on reef and wreck structure, as Infinite Blue’s wreck trip works it. The same approach carries over to the grounds above: the wreck at Thunderbolt, and the rubble and concrete at the bridge sites. General technique is covered in our reef fish guides.
Who fishes for red grouper out of Marathon
Two local charters list red grouper. Their water and boats show where the local effort goes.
Ana Banana Fishing Company
Ana Banana Fishing Company is run by Captain Joel Brandenburg on a 1975 40-ft Hatteras with twin Detroit Diesel engines. The boat works rocky areas and artificial reefs in 30-100 ft.
Infinite Blue Charters
Infinite Blue Charters is run by Captain Robert Williams. The boats are Happy Ours II, a 47-ft Sea Ray, and a Wellcraft 290 Coastal. The wreck and bottom trip runs 40-200 ft, bottom fishing on reef and wreck structure. Fishing picks up in the cooler months.
| Operator | Captain | Boats | Water |
|---|---|---|---|
| Ana Banana Fishing Company | Joel Brandenburg | 1975 40-ft Hatteras, twin Detroit Diesel | 30-100 ft, rocky areas and artificial reefs |
| Infinite Blue Charters | Robert Williams | Happy Ours II (47-ft Sea Ray), Wellcraft 290 Coastal | 40-200 ft, rocky bottom and structure |
FAQ: red grouper fishing out of Marathon
When is red grouper closed off Marathon?
January-April is closed season, per local operators. Confirm with FWC before you fish.
What depth should I start in?
Start in 30-100 ft on rocky areas and artificial reefs, then work 40-200 ft rocky bottom. In the cooler months fish move shallower.
How far is Thunderbolt?
Thunderbolt sits in 120 ft, 4 miles south of Marathon and Key Colony Beach.
Is the Marathon Hump red grouper water?
No. Its shallowest point is 480 ft, beyond the 200 ft edge of the listed range. The 409 Hump is known as a blackfin tuna spot.
Which charters target red grouper out of Marathon?
Infinite Blue Charters (Capt. Robert Williams, 40-200 ft) and Ana Banana Fishing Company (Capt. Joel Brandenburg, 30-100 ft).
