Opinicon Lake – Chaffey's Lock

About this water

Queen's University Biological Station sits on this lake, and the bass and pike fishing is as good as it gets for shore and small-boat anglers.

Shallow, warm, weedy lake on the Rideau system. Lily pad fields and submerged timber. Stained water.

FMZ 18 regulations — Eastern Ontario — Rideau & inland southeastern watersheds

Southeastern Ontario, built around the connecting lakes and rivers of the Rideau waterway, with the Canadian Shield at its heart and the St. Lawrence Lowlands to the east and west. It covers the Crowe, Mississippi, Napanee, Cataraqui, Rideau, Salmon, South Nation and Raisin River watersheds. It ends at Lake Ontario and the St. Lawrence River to the south (FMZ 20) and follows the Ottawa River (FMZ 12) to the north and east — the Ottawa and St. Lawrence Rivers themselves are not in FMZ 18.

• Walleye: 3rd Saturday in May – March 15; S-4/C-2.
• Muskie: 3rd Saturday in June – Dec 15; 137 cm min, S-1/C-0.
• Bass (large & small): 3rd Saturday in June – Nov 30; S-6/C-2.
• Lake trout (Big Rideau, Charleston): Jan 1 – Sept 30; S-2/C-1.

Zone check: FMZ 18 confirmed from this water's coordinates against the official Ontario zone boundaries (reviewed 2026-08-12).

Summary only — always confirm current seasons and limits on the Ontario MNRF FMZ 18 page before your trip.

Seasonal availability

Open-season windows for the species found at Opinicon Lake – Chaffey's Lock, taken from the FMZ 18 regulation summary. Green months are within a published open season — they are not a prediction of how well fish will bite.

No FMZ 18 season line published in our summary for: Northern Pike, Panfish, Black Crappie. Check the official page before keeping these species.

Summary only, and seasons change annually. Confirm dates on the Ontario MNRF FMZ 18 page before your trip.

Fishing tips

• St. Lawrence smallmouth relate to current — drop-shot the drop-offs.
• Thousand Islands muskie respond to figure-8s at boatside — always finish the retrieve.
• Opinicon is a frog fishing paradise. Cast topwater frogs over the lily pads and hold on. Pike patrol the weed edges — white spinnerbaits ripped fast draw violent strikes.
• Access: Free parking at Chaffey's Lock station. Small public launch for canoes and small boats.

Gear setup

Setup:

Medium spinning for bass; medium-heavy for pike; ultralight for panfish

Rod:

6'6" medium spinning

Reel:

Size 2500 spinning

Line:

10 lb braid with 8 lb fluorocarbon leader

Best bait:

Worms, Leeches, Minnows

Best lures:

Topwater frog, Chatterbait, Spinnerbait (white), Texas-rigged creature bait