The Shannon Lake Ireland
Two quiet branches at the top of the Shannon: the Boyle River through Cootehall and Clarendon Lock to the wooded islands of Lough Key and the harbour at Boyle, and the little Lough Allen Canal from Battlebridge to Drumshanbo and the open reservoir lake below the Iron Mountain.
Days and hours are our estimate: 7.5 km/h and 15 minutes a lock, about six hours a day.
Start from a ready-made trip, or plan your own day by day: distances, locks and overnight moorings.
Above Carrick-on-Shannon two quiet branches leave the main river, and both are dead ends well worth the detour. To the west the Boyle River winds through Lough Drumharlow and past the village quay at Cootehall to Knockvicar, where Clarendon Lock lifts boats onto Lough Key. The lake is small but full of wooded islands: Castle Island with its folly castle, Trinity Island with the ruined abbey where the Annals of Loch Cé were written, and the shore of Lough Key Forest Park, with a public marina, a café and plenty to do ashore. A short canal cut then leads to the harbour at Boyle, a market town with a Cistercian abbey and a Georgian mansion. To the north, above Leitrim village, the Lough Allen Canal climbs through three small locks from Battlebridge past Acres Lake to Drumshanbo, home of the Shed Distillery and a week of traditional music every July. Beyond the last lock opens Lough Allen, a wide reservoir lake under Sliabh an Iarainn, with Waterways Ireland moorings at Cleighranmore and Spencer Harbour.
13 stops from Cootehall to Spencer Harbour.
Desk research, not yet checked on site
A riverside village on the Boyle River with a small public quay by the bridge, a waterfront restaurant and the barracks that John McGahern made famous.
Photo: Oliver Dixon · CC BY-SA 2.0
A small village where the Boyle River leaves Lough Key, with public moorings at the bridge, a towpath to Clarendon Lock and a large private marina just downstream.
Photo: Sarah777 · Public domain
The only lock on the Boyle River: a keeper-operated lock beside the weir at Knockvicar that lifts boats from the river onto Lough Key.
Photo: Suse · CC BY-SA 2.0
The tiny island off Lough Key Forest Park crowned by McDermott’s Castle, a medieval stronghold remade as a romantic folly, to be admired from the water only.
Photo: Carlo Cretaro · CC BY 2.0
The main public marina of the Boyle River branch, at the foot of an 800-acre forest park with a café, a treetop walk, a viewing tower and boat trips.
Photo: Sarah777 · CC BY-SA 2.0
A wooded island on Lough Key with the ruined Holy Trinity Abbey, where monks kept the medieval Annals of Loch Cé.
The head of navigation on the Boyle River: a canal-cut harbour a short walk from a market town with a great Cistercian abbey and the Georgian King House.
The entrance to the Lough Allen Canal near Leitrim village: a keeper-operated lock close to a 200-year-old riverside pub and campsite with a private marina.
Photo: Suse · CC BY-SA 2.0
The middle lock of the Lough Allen Canal, in quiet farmland about halfway between Battlebridge and Acres Lake.
Photo: Suse · CC BY-SA 2.0
The canal-head town at the foot of Lough Allen, with Waterways Ireland moorings, a jetty on Acres Lake, a floating boardwalk, the Shed Distillery and a week of traditional music each July.
Photo: tower10 · CC BY-SA 3.0
The top lock of the Lough Allen Canal at Blackrock, the gateway from Drumshanbo onto the open waters of Lough Allen.
Photo: Oliver Dixon · CC BY-SA 2.0
A Waterways Ireland marina on the east shore of Lough Allen, below Sliabh an Iarainn near Ballinagleragh.
Photo: Dieglop · CC BY-SA 4.0
A small 19th-century harbour on the north-west shore of Lough Allen near Drumkeeran, with overnight moorings and a lakeside picnic area.
Photo: Andreas F. Borchert · CC BY-SA 4.0
Also on this waterway: Carrick-on-Shannon (Upper Shannon: Lanesborough to Carrick) · Leitrim Village (Shannon–Erne Waterway)
Pump-out, water, fuel, shore power, showers and laundry where a listing says so, in route order. Tap a stop for who runs it and when.
A stop not listed here may still have them: nobody has checked yet. Know better? Report a change
Mooring limits, locks, speed and hazards, in our own words with links to the sources.
Lough Key, the Boyle River and Lough Allen are part of the Shannon Navigation: at public harbours and jetties you may stay up to 5 days in a row, or 7 days in a month, all year unless you have a winter mooring. Winter mooring (1 November–31 March) is booked online, and water and power at public moorings are off then (boater information, Marine Notice 107/2026).
All four locks are worked by lock-keepers. Hours in 2026: April–September 09:30–19:30 Monday to Saturday, late March and October until 18:30, Sundays 09:30–18:00; 1 November–13 March mornings only; lunch break 13:00–14:00. A passage costs 2 Smart Card units or €1.50. Clarendon: +353 71 966 7011. The canal locks share one lock-keeper line, so ring ahead: +353 86 812 7522 or +353 71 964 1552. Most maintenance is between 1 November and 17 March: ask Waterways Ireland if the route is open. Lifejackets or buoyancy aids are compulsory in and beside locks (Marine Notice 35/2026).
The same card opens the Waterways Ireland service blocks at Lough Key, Boyle and Drumshanbo and pays for showers, pump-outs and shore power (none at Boyle) (shop).
The Lough Allen Canal locks are 19.5 m long and 4 m wide; as a guide the canal takes 1.2 m draft and 3 m air draft.
At Knockvicar a boom guards the weir beside Clarendon Lock: keep to the lock side. Lough Allen is a reservoir, so its level can rise and fall by well over a metre (OPW gauge at Blackrock Lock), and it is big and open: keep to the marked channel and check the forecast. Until September 2027 works at Hartley Bridge, between Carrick and Leitrim, restrict boats to the centre arch, and boats heading upstream give way (Marine Notice 53/2026).
This is a travel guide, not a navigation aid.
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4 locks on this waterway. The times below are worked out on this device. They change with the season: always read the notice.
All lock and bridge times Check the Waterways Ireland marine notices
Ready-made trips that start here or pass through.
Photo: Andreas F. Borchert · CC BY-SA 4.0
Photo: Oliver Dixon · CC BY-SA 2.0
Photo: tower10 · CC BY-SA 3.0
No events listed for this waterway yet.
Current Waterways Ireland marine notices for this waterway. The one-line summaries are ours: read the notice itself.
Source: Waterways Ireland · All marine notices on Waterways Ireland
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