The harbor is often ignored by cruising boaters due to the somewhat undeserved reputation as a "difficult approach." But, in fact, a strong (>20 knots) southwest wind , a large ocean swell (caused, say, by an ocean storm passing to the south) and an ebb tide can combine to form a dreaded "breaker on the inlet bar" condition at the mouth of the harbor. Yet this condition occurs on fewer than five days out of a typical May to October boating season. (In Prohibition Days, the Rum Runners would relish "breaker" conditions (more common, by the way, in the Winter months) to offer protection from pursuing Revenue Cutters.)

Whether approaching from the north or south, pick up Can 5 due south of the river mouth. This Can marks the southern edge of the infamous "bar" which extends to within 100 yards of the river entrance. Long before approaching the Can you will know if the breakers are running. If so, you can await the change of tide in the lee of Two-mile Rock or abort to Sakonnet Harbor to the southwest or Padanaram Harbor to the northeast.

Assuming normal conditions, you will remain in six (6) feet or more of water throughout the approach by closely following the navigation buoys (Nuns 6, 8 & 10). The entrance is protected to the south by an very large imposing bedrock outcropping known as Mt. Knubble (or "The Knubble" or the "Spindle": Fl G 6 sec 31 ft (10 M) "5"). The ground directly to the south of (i.e. outside of) the Knubble is quite broken and should be avoided. However, the channel extends right up to the backside of the Knubble with deep water and no obstructions. To the right of the channel lies the partially submerged Half-Mile Rock. The buoyed channel gives this beastie a wide berth. Once inside of the Knubble the channel deepens to 20 feet or more. Here you will experience the strongest tides that the river has to offer. Expect 2 to 4 knots outbound maximum ebb speed (which depends on rainfall and seasonal height of the tide, consult "Eldridge Tide and Pilot Book" for specifics) and a healthy 2 to 3 knots inbound at flood-max.

Cape Cod Fisherman's Alliance

Mass Environmental Police

U.S. Coast Guard
Cape Cod Office Contact Info

U.S. Army Corps of Engineers 
New England District
696 Virginia Road
Concord, MA 01742