Dodd Narrows — BC, Canada

Dodd Narrows connects Stuart Channel with Northumberland Channel, between Vancouver Island and Mudge Island just south of Nanaimo. Purvis Point and Joan Point, its two sides, are about 0.1 mile apart. It is used mainly by tugs with barges and log booms, and by small craft. (PAC 201)

How the narrows behave

The flood runs north to a maximum of 9.5 knots, and the ebb runs south to 8.5 knots. With the stream at strength, rips form where it meets its own counterflow — off the north entrance on the flood, and near the overhead power cable on the ebb. The Sailing Directions advise holding course in the main stream until clear of that turbulence. (PAC 201)

The narrows are harder going north to south. Coming from the north, the slight course change has to be made the moment you enter the narrow part, and the entrance is hard to see from Northumberland Channel. (PAC 201)

How slack works here

Dodd Narrows is a reference current station: the Canadian Hydrographic Service tabulates its slack water and maximum currents in the Canadian Tide and Current Tables, Volume 5. False Narrows, on the other side of Mudge Island, is referenced on it. (PAC 201)

On the water, the rips are the sign. As the stream slackens they gradually disappear. (PAC 201)

Planning a transit

The Sailing Directions recommend going through at slack water. Before going through at any other time, be sure the vessel can make headway against the stream, and wait for slack if in doubt. Slack is also when traffic is heaviest, but the narrows are short and easy with a good lookout and respect for other vessels. (PAC 201)

Don't hinder tugs with barges, and listen for the sound and radio signals used in narrow channels. Vessels up to 70 m have passed through at slack, but the narrows are not a recommended passage for larger craft. (PAC 201)

An overhead power cable with 45.7 m vertical clearance crosses about 0.2 mile south of Purvis Point. The southwest limit of Nanaimo Harbour crosses the narrows, and harbour regulations apply north of it. (PAC 201)

Percy Anchorage, at the west end of False Narrows, is a convenient place to wait for slack. (PAC 201) Joan Point Park, on the Vancouver Island side, overlooks the narrows from shore. (City of Nanaimo)

Nearby

North of the narrows, Northumberland Channel leads northwest to Nanaimo and the Strait of Georgia; its stream sets east almost continuously, at 1 to 2 knots at springs. (PAC 201)

False Narrows, south of Mudge Island, is the other way between Pylades Channel and Northumberland Channel. It is suitable only for small craft with local knowledge: it is shallow, choked with kelp in summer and autumn, and log booms are towed through it. (PAC 201)

Gabriola Passage leads east from Pylades Channel into the Strait of Georgia. Its flood sets east to 8.5 knots and its ebb west to 9, and it should be taken only at slack by those who know it. (PAC 201)