When mahi show up off Plymouth
Mahi-mahi are a summer bonus off Plymouth, not a fishery you plan a trip around. There is no documented mahi fishery here, only mentions. If you run your own boat from Plymouth, this page covers what is known, where boats run, and how to be ready if one shows.
Summer warm water
Cuz Charters’ reports page says Gulf Stream warm water pushes warm-water species toward shore in summer. That is the only stated reason a warm-water fish turns up in Cape Cod Bay waters, which makes summer the window.
For the regional picture, see the Atlantic Northeast picture (see also the Atlantic Northeast region guide). For biology, floating weed and general habits, read our mahi-mahi fishing guide.
What to expect
Encounters are occasional and come on offshore trips, not inside the bay. 1620 Anglers says offshore trips may encounter mahi, so treat one as a bonus on a trip you already planned rather than the reason for it.
Where boats run from Plymouth
Mahi encounters belong to the offshore run, so that is where the decision starts. Three things shape it: the landmark you pass on the way out, the one distance we can give you, and the buoy you read before you leave the dock.
- Exit: past The Gurnet
- Distance baseline: Race Point, 22 nm
- Conditions source: NDBC 44090
Out past The Gurnet
The Gurnet is the landmark boats pass on the way out of Plymouth Bay to open water. Use it as your first waypoint on the run.
Race Point, 22 nm
Race Point is 22 nm from the Plymouth Harbor ramp, per Currents. Use that figure as a baseline for fuel and trip-length planning on your own boat. It is the only distance on this page.
Reading conditions
The nearest buoy is NDBC 44090, the Cape Cod Bay waverider buoy. Read wave height and wave period as numbers before the run, then check the NWS Cape Cod Bay forecast for the official word.
Before you commit, look at water temperature and bottom contours in the OBS SST and Chart Contours layers. The chart layers are not for navigation.
Grounds and structure
These are the named grounds and marks around Plymouth. Notes appear only where a source gave one.
| Ground | Known note |
|---|---|
| Stellwagen Bank | Named ground near Plymouth |
| Jeffreys Ledge | Named ground near Plymouth |
| Race Point | 22 nm from the Plymouth Harbor ramp (Currents) |
| Crab Ledge | East of Chatham. A bluefin ground (1620 Anglers) |
| Regal Sword | Named ground near Plymouth |
| The Gurnet | Named mark near Plymouth |
| The hole by Bug Light | In Plymouth Bay |
| Billingsgate Shoal | A Cape Cod striper hot spot (Plymouth Charters) |
No ground listed here is documented as mahi water.
Stellwagen Bank and Jeffreys Ledge
Stellwagen Bank and Jeffreys Ledge are the offshore grounds on the Plymouth list. Offshore trips go there, so a bonus mahi would be possible, though neither is documented as holding them.
Crab Ledge and the Regal Sword
Crab Ledge sits east of Chatham and is a bluefin ground, per 1620 Anglers. The Regal Sword is another named ground on the list. Bluefin trips are the trip type where a mahi could turn up.
Inshore names: Bug Light hole and Billingsgate Shoal
Both are inshore or striper context rather than mahi water. The hole by Bug Light is in Plymouth Bay. Billingsgate Shoal is a Cape Cod striper hot spot, per Plymouth Charters.
How mahi are fished out of Plymouth
The local approach is to be ready on an offshore trip. There is no dedicated mahi program out of this port to copy.
A bonus on offshore trips
Mahi are fished opportunistically on offshore trips, most of them bluefin tuna trips. 1620 Anglers says offshore trips may encounter mahi, and Black Rose lists mahi mahi among the fish its boat has caught. For the other offshore species boats target on these runs, see the offshore gamefish guides.
Being ready for one
- Watch the water on the run.
- Know that a warm-water fish is possible in summer.
- Have a plan so a sighting does not derail the tuna trip.
Tackle detail is in the mahi-mahi species guide linked above.
Who fishes for them
If you want local knowledge before going out on your own boat, start with the operators who list mahi or describe warm-water encounters.
Black Rose Fishing Charters
Black Rose Fishing Charters runs the boat Black Rose under Rich Antonino. Black Rose lists mahi mahi among the fish its boat has caught.
Other Plymouth operators
1620 Anglers says offshore trips may encounter mahi and names Crab Ledge as a bluefin ground. Cuz Charters’ reports page is the source on the summer warm-water push.
FAQ
Are mahi a realistic target out of Plymouth?
Not as a plan. There is no documented mahi fishery here, only mentions. 1620 Anglers says offshore trips may encounter mahi, so treat one as a possible extra on a trip you already planned.
When are they around?
Summer. Cuz Charters’ reports page says Gulf Stream warm water pushes warm-water species toward shore in summer, and that push is the stated reason a warm-water fish appears off Plymouth. We do not give months.
How far is Race Point from the ramp?
Race Point is 22 nm from the Plymouth Harbor ramp, per Currents. Use that number as a planning baseline for fuel and trip length on your own boat.
Which buoy do I check?
NDBC 44090, the Cape Cod Bay waverider buoy. Read wave height and wave period as numbers before you run, then check the official forecast, and decide from those numbers.
Does any Plymouth charter list mahi?
Black Rose Fishing Charters, with Rich Antonino on the boat Black Rose, lists mahi mahi among the fish its boat has caught. 1620 Anglers says offshore trips may encounter mahi.
