What the Thames River offers anglers in Groton

The Thames River runs through Groton and holds striped bass, shad, and white perch in predictable seasonal patterns. The river is tidal from the mouth near New London up through Groton, which means water levels and fish movement follow the tide rather than rainfall. Access is straightforward—public boat launches exist at Groton Long Point and near the Submarine Base, and you can wade or fish from shore in several spots. The best fishing happens in spring (April through May) when shad run upriver, fall (September through October) when stripers move through, and winter (December through February) when white perch school in deeper holes.

The Thames is narrower and shallower than the Connecticut River to the west, which changes how fish use it. Stripers here are often smaller—12 to 18 inches is common—but the river holds enough 20-plus-inch fish to make it worth your time. Shad fishing is the real draw in spring; the run is reliable and the fish are aggressive. The river also sits close to Long Island Sound, so saltwater species like bluefish and weakfish show up in late summer and early fall.

Key Takeaways

  • Spring shad runs (April through May) bring the most consistent action, with fish moving upriver on rising tides through Groton's main channel.
  • Striped bass fishing peaks in fall (September through October) when larger fish move through on their way to wintering grounds.
  • Public boat launches at Groton Long Point and near the Submarine Base give you access without private property hassle.
  • White perch school in deep holes during winter and are easiest to find in December and January when water is cold and clear.
  • Tide matters more than time of day on the Thames—fish feed actively during the first two hours of incoming tide and the last two hours of outgoing tide.

Spring shad fishing: April through May

Shad move upriver from Long Island Sound in April and May, following warming water temperatures. They travel on the incoming tide and rest in deeper holes on the outgoing tide. The main channel through Groton—roughly between Groton Long Point and the Submarine Base—is where most shad pass through. Fish small shad darts (1/4 to 3/8 ounce) in white, chartreuse, or pearl colors on a 6-foot spinning rod with 8-pound test. Cast uptide and let the dart swing through the current, then retrieve with short jerks.

The first two hours of the incoming tide are most productive. Shad feed aggressively during this window and will hit a dart repeatedly. Water temperature matters: shad bite best when the river is between 50 and 65 degrees. Early April can be slow if the river is still cold; late April and early May are usually peak. Wading from the banks near Groton Long Point works if you do not have a boat, though a small skiff lets you cover more water and reach the deeper channel where larger shad hold.

Fall striped bass: September through October

Stripers move through the Thames in fall on their way south to wintering grounds. They are larger and more aggressive than spring fish, and they feed heavily to build energy for migration. September is hit-or-miss; October is more reliable. Fish the deeper holes and channel edges where stripers rest between feeding runs. Live herring or mackerel work well, as do larger shad darts (3/8 to 1/2 ounce) and small topwater plugs.

Outgoing tide is often better than incoming in fall—stripers use the current to move downriver and feed as they go. Fish the last two hours of the outgoing tide and the first hour after it turns. The water is still warm in September (65 to 70 degrees), which means stripers are active and will chase moving baits. By October, water temperature drops to 55 to 60 degrees, and fish slow down slightly but feed more predictably in deeper holes. Groton Long Point and the channel near the Submarine Base are both productive.

Winter white perch: December through February

White perch are the winter fish on the Thames. They school in deep holes and move very little once water temperature drops below 45 degrees. The deepest water in Groton is near the Submarine Base, where the river channel reaches 30 to 40 feet. Fish small jigs (1/8 to 1/4 ounce) tipped with live shiners or small shad. Drop the jig to the bottom, then work it with short lifts and pauses. White perch will bite aggressively once you find the school.

Winter fishing requires a boat—wading is not practical in deep water. The bite is steadiest in December and January when water is coldest and fish are most concentrated. February can be slower as water begins to warm and fish start to disperse. Tide matters less in winter than in other seasons; fish feed throughout the tide cycle, though the first hour after the tide turns often produces a quick flurry. Bring warm clothes and a thermos; winter fishing on the Thames is cold work, but the action can be fast once you locate the school.

Access points and boat launches

Groton Long Point has a public boat launch managed by the town. The ramp is concrete, well-maintained, and has parking for trailers. It sits at the mouth of the Thames where the river meets Long Island Sound, which means you can fish the river or run out to sound waters depending on conditions. There is a launch fee, typically a few dollars for a day pass. The ramp gets busy on weekends, especially in spring and fall.

A second launch exists near the Submarine Base on the west side of the river. Access is more limited here—you will need to check current restrictions with the base or the town of Groton, as military property borders the area. Call ahead before you go. Both launches give you access to the main channel and deeper holes where most fish hold. If you do not have a boat, wading from the banks near Groton Long Point is possible during low tide, though you will cover less water than from a boat.

Tackle and technique for Thames River fishing

A 6-foot spinning rod with 8- to 12-pound test works for all Thames River fishing. Shad darts are the most versatile lure—they work for shad, stripers, and white perch. Keep a range of sizes (1/4 to 1/2 ounce) and colors (white, chartreuse, pearl, and natural shad patterns). Small topwater plugs (2 to 3 inches) are deadly for stripers in fall, especially early morning or late evening. Live bait—herring, mackerel, or shiners—works year-round but requires more setup and is messier to transport.

Tide is the most important factor on the Thames. Incoming tide pushes fish upriver and triggers feeding; outgoing tide moves fish downriver. The first and last two hours of each tide phase are most productive. Slack tide (the moment between incoming and outgoing) is usually slow. Check tide tables for New London, which is close enough to Groton to be accurate. Water temperature also matters: shad bite best between 50 and 65 degrees, stripers between 55 and 70 degrees, and white perch below 45 degrees.

Seasonal patterns and what to expect month by month

March is slow—water is cold and fish are still in deeper wintering grounds. April brings the first shad, though early April can be hit-or-miss if water temperature is still below 50 degrees. May is peak shad season; fish aggressively and the runs are reliable. June through August are slow for shad and stripers; white perch move deeper and are harder to find. July and August can be good for bluefish and weakfish if you run out to the sound.

September brings the first fall stripers, though they are often small and scattered. October is peak fall striper fishing; larger fish move through and bite aggressively. November is a transition month—stripers are leaving and white perch are moving into winter holes. December through February are white perch season; fishing is slow but steady if you find the schools. The bite picks up again in March as water warms and shad begin their spring migration.

Frequently Asked Questions

Do I need a Connecticut fishing license to fish the Thames in Groton?

Yes. Connecticut requires a fishing license for anyone 16 and older. You can purchase a license online through the Connecticut Department of Energy and Environmental Protection (DEEP) or at most tackle shops. A short-term license (3 days) costs less than an annual license if you fish only occasionally.

What is the best tide to fish the Thames?

The first two hours of incoming tide and the last two hours of outgoing tide are most productive. Fish feed actively during these windows. Slack tide (the moment between tides) is usually slow. Check tide tables for New London to time your fishing.

Can I catch stripers year-round on the Thames?

Stripers pass through in spring (April and May) and fall (September and October). Summer and winter are slow for stripers. Winter white perch and spring shad are more reliable if you fish outside the striper seasons.

Is the Submarine Base launch open to the public?

Access is limited due to military property. Call the town of Groton Parks and Recreation or check the Groton website before you go. Groton Long Point is your safest bet for a public launch without restrictions.

What size shad darts work best for Thames River shad?

1/4 to 3/8 ounce darts work for most conditions. Use 1/4 ounce in slower current or shallow water, and 3/8 ounce in faster current or deeper holes. White, chartreuse, and pearl colors are most reliable.