Circumnavigating Cape Ann
It’s about 22 miles around Cape Ann. The Blackburn Challenge winners do it in just over 2 hours – if you’re doing it for the first time, you might want to allow for a more leisurely pace of between 6 and 8 hours.
When planning your trip, check the tide charts for Rockport and Gloucester. If you can time the tide so that you enter the Annisquam on an inbound tide, and exit on an outgoing tide, you've done the best you can.
The mid-point of the river from a standpoint of "which way does the tide flow?" seems to be between the railroad bridge and the 128 bridge, so if you are going clockwise, you want to be there at exactly high-tide. The worst thing to do would be going on the north stretch of the river against the tide – this is painfully slow.
People in the know say that the direction (clockwise or counter) is not as big an issue as the tide. The route shown below goes counterclockwise, leaving from Rockport Harbor.
Good luck - bring plenty of fluids!
Counterclockwise route leaving from Rockport Harbor with waypoints, convenient bailout points (roads), cumulative distances and estimated times at the waypoints (based on average speed of 3 knots/hr).
Circumnavigation Chart with marked waypoints
Blackburn Challenge Course