Boating from Lake Couchiching: routes, locks and launches

Lake Couchiching is a hinge on the Trent-Severn Waterway. Head south and you're on Lake Simcoe in minutes, with no lock in between. Head north and Lock 42 at Washago drops you onto the Severn River, which runs through a string of lakes, locks and the Big Chute Marine Railway to Georgian Bay. For a waterfront owner, that means one of the most flexible home ports in the region.

Rossmanteam.com's water levels, boating and ice guide covers lock hours and invasive-species rules. This page focuses on routes, clearances and where to launch or keep a boat.

How do you get from Couchiching to Lake Simcoe?

Through the Atherley Narrows at Orillia's south end. There's no lock; the two lakes are managed together. Things to know:

• Stay in the marked channel. Parts of the Narrows bottom are the Mnjikaning Fish Weirs National Historic Site, and the navigation channel has been dredged since 1856–57. Parks Canada's management statement notes the weirs are vulnerable to boating activity.
• Clearance. The fixed Highway 12 bridge has 7.0 m (22.8 ft) of clearance at normal navigation-season levels. The former CN swing bridge beside it is locked open.
• Big water ahead. Lake Simcoe is far larger than Couchiching, and wind and waves build quickly. For Simcoe-side detail, see simcoewaterfronthomes.com.

More on living at the Narrows is in Atherley and the Narrows.

How do you get from Couchiching to Georgian Bay?

North through Lock 42 and down the Severn. Here's the sequence from Parks Canada's navigation data (km from Trenton, with distance to Port Severn):

Point	km	To Port Severn	Notes
Muskoka Road bridge	335.2	51.9 km	6.7 m clearance
CN swing bridge	336.6	50.5 km	About 3.96 m closed; trains have priority
Lock 42 – Couchiching	337.8	49.3 km	6.2 m lift; 47.2 m x 9.7 m chamber
Couchiching Lock bridge	337.8	49.3 km	9.4 m clearance
Hamlet swing bridge	342.4	43.7 km	Swing bridge
Lock 43 – Swift Rapids	361.2	25.9 km	14.3 m lift; 36.6 m x 9.7 m
Lock 44 – Big Chute Marine Railway	374.1	13.0 km	Carriage 30.5 m x 7.3 m; 17.7 m lift
Lock 45 – Port Severn	387.1	0	3.7 m lift; 25.6 m x 7.0 m

Parks Canada notes bridge clearances are based on normal navigation-season levels. At Big Chute, operators of vessels over 68 tonnes, with unusual hull shapes or other lifting concerns must call 705-756-8802 at least 48 hours ahead.

Below Washago the river flows north into Sparrow Lake, then turns west and south toward Gloucester Pool, with Big Chute just before it. For buying on the Severn itself, see rossmanteam.com's Severn River cottage guide.

When are the locks open?

In 2026 the locks ran May 15 to October 12, with longer hours from June 19 to September 7. Parks Canada says times aren't guaranteed and can change for water management or maintenance. Lock 42 is "a very busy lock station on weekends," so a weekday start helps. Navigation is closed from Thanksgiving to Victoria Day.

What are the speed and wake rules?

• Ontario's shoreline rule. No power-driven or electric vessel faster than 10 km/h within 30 m of shore on Ontario waters. Exceptions include towing a skier or tuber on a course straight away from and perpendicular to shore, and operating in rivers under 100 m wide, canals and buoyed channels.
• Trent-Severn zones. Parks Canada says more than 75 speed limit zones are posted along the waterway's navigation channels, marked with arrow-shaped boundary signs and round limit signs, and police patrol them. The limit is normally 10 km/h on the canal sections.
• Wake. You're responsible for your wake. Be especially careful near docks at the Narrows, the Port of Orillia and the Washago entrance to the Severn.

Where can you launch or keep a boat?

Place	What's there
Centennial Boat Launch, Orillia	50 Centennial Drive; parking for 19 vehicles with trailers plus standard spaces
Port of Orillia	220 transient slips, boats up to 80 ft and 5 ft draft, 30/50 amp power, launch ramp and fishing pier; open May through September; no seasonal dockage
Quetton Street, Washago	Municipal dock near Washago Centennial Park, start of Severn's Lake Couchiching paddling route
Albany Street, Washago	Municipal dock on the Green River
Private marinas	Severn lists McGregor on the Water Marina and Lauderdale Point Marina among Couchiching boating access points

Launch and trailer-parking fees and rules change, so check with the City of Orillia, Severn or Ramara before you go.

What does this mean when you're buying?

• Air draft. If your boat is tall, the CN swing bridge above Lock 42 (about 3.96 m closed) will shape your trips north. The Narrows bridge (7.0 m) matters for Simcoe runs.
• Draft and depth. Couchiching's mean depth is about 6 m, but many shorelines are shallow. Make sure the dock has depth for your boat after the fall drawdown (see water levels and seasons).
• Position on the lake. A lot near the Narrows is quickest to Simcoe; a lot near Washago is quickest to the Severn. Open-lake lots in the middle get the most wind.
• Storage. If the property lacks a boathouse or good frontage, budget for a marina slip and winter storage.

How Jordan can help

Jordan can help you match a property to the way you boat: Simcoe runs, Severn cruising, or a quiet paddle off the dock. He can point out where on the lake each listing sits relative to the Narrows, the locks and open water. Call 705-345-0797 or get in touch below.