Where boats run from these harbors
Black sea bass fishing out of Barnstable and Cape Cod Bay harbors centers on a short list of named grounds, each at a known depth. This guide covers those grounds, which harbor pairs with which ground, and who runs trips. For ramps, channels and forecast details, use the Barnstable and Cape Cod Bay port page. For the wider coast, see the black sea bass fishing in the Atlantic Northeast and the Atlantic Northeast offshore fishing guide.
Most of the ground falls between a 15 ft shoal top and water 80 to 90 ft deep. Each harbor sets you up for part of that range.
Sesuit Harbor
Sesuit Harbor is the jumping-off point for the open-water school area at 80 ft, out in Cape Cod Bay. Dragonfly Sportfishing launches here.
Rock Harbor
Rock Harbor is home to a charter fleet that lists sea bass among its targets. Billingsgate Shoal and "The Square" sit on the east side of the Bay.
Barnstable Harbor
Barnstable Harbor is one of the same group of Cape Cod Bay harbors, and boats from here fish the same named Bay grounds listed below.
When the fish are around
Sea bass move in and out of the Bay with the seasons, so timing depends on the species rather than the port. The black sea bass species guide covers the seasonal movement.
Grounds and structure that hold sea bass in Cape Cod Bay
The grounds run from a 15 ft shoal top to 80 and 90 ft water, with Stellwagen Bank beyond.
| Ground | Depth (ft) | Reference |
|---|---|---|
| Billingsgate Shoal | 15 (top rarely deeper) | East side of the Bay |
| Open water off Sesuit | 80 | Out into the Bay from Sesuit Harbor |
| "The Square" | 90 | West of Billingsgate Shoal |
| Brewster and Dennis reef (proposed) | – | Not confirmed built |
| Stellwagen Bank | – | Offshore |
Billingsgate Shoal
The top of Billingsgate Shoal is rarely deeper than 15 ft. Plot it before you run and plan your approach around that number.
"The Square"
"The Square" is the old-timers’ name for the deeper water west of Billingsgate Shoal, at 90 ft.
Open water off Sesuit
This school area sits at 80 ft, out in Cape Cod Bay from Sesuit Harbor.
Proposed Brewster and Dennis reef
The Brewster and Dennis artificial reef is proposed and not confirmed built, so don’t plan a trip around it. For background on this kind of ground, see how structure-oriented bottom fish are fished.
Stellwagen Bank
Stellwagen Bank is the offshore option beyond the Bay grounds. It is a longer run, aimed at anglers who want to go past the Bay.
How depth shapes the local approach
Depth is the first decision. The 15 ft shoal top and the 80 to 90 ft open water are different places to set up, and the ground you choose determines most of the rest of the day. Stellwagen Bank extends that choice offshore for anglers willing to run farther.
On the map, the Chart Contours layer shows the change from the 15 ft shoal top to the 90 ft water of "The Square." Chart layers are not for navigation.
The NWS Cape Cod Bay forecast gives wind, wave height and period as numbers. Read it before you run.
Who fishes for them out of Barnstable and Cape Cod Bay
Two local operators list black sea bass.
Rock Harbor Charter Service
The Rock Harbor Charter Service fleet lists sea bass among its targets. Boats on the site include:
- Columbia (Capt. Marc Costa)
- Stunmai II
Dragonfly Sportfishing
Dragonfly Sportfishing is run by Capt. Mike Bosley and launches from Sesuit Harbor. The operation has a black sea bass trip page.
FAQ about black sea bass out of Barnstable and Cape Cod Bay
How deep is Billingsgate Shoal?
The top is rarely deeper than 15 ft. The deeper water west of it, known as "The Square," is 90 ft.
What is "The Square" in Cape Cod Bay?
It is the old-timers’ name for the 90 ft water west of Billingsgate Shoal.
Where do sea bass school off Sesuit Harbor?
In open water at 80 ft, out in Cape Cod Bay from Sesuit Harbor.
Is the Brewster and Dennis artificial reef built?
It is proposed and not confirmed built.
Which charters run sea bass trips from these harbors?
Rock Harbor Charter Service runs Columbia (Capt. Marc Costa) and Stunmai II. Dragonfly Sportfishing runs out of Sesuit Harbor with Capt. Mike Bosley.
