|
Tides & Currents
Tidal currents throughout Boston Harbor are relatively strong (more than one knot at maximum speed). Therefore, to maximize efficiency this trip should be timed to run with the currents.
Fortunately, currents through the outer islands generally ebb to the east and flood to the west. By leaving Hull on the ebb and reaching the Graves at low-water slack, paddlers can get a boost from the current for the entire trip.
NOAA's Tidal Current Tables provide significant data on Boston Harbor currents, so it is easy to obtain predictions from Dansm's Tidal Current Calculator. To display sample current predictions for locations along the trip route, click here.
Tide predictions are available for a number of locations throughout the harbor, but neither the timing nor the height varies much from station to station. Therefore, we'll pick Boston Light as a representative location.
During the trip, keep an eye on the water level, because there are numerous mudflats and sandbars that are exposed at low tide. Remember, never rely on the timing of the tide to predict tidal currents.
Planning Your Trip
Following the route shown on the trip map, the distance from Hull to the Graves is 5.5 nautical miles. The return distance via Little Brewster Island is also 5.5 miles.
Travel Times: Hull to the Graves |
|
|
paddling speed |
2 knots |
3 knots |
4 knots |
5.5 nautical miles |
2:15 |
1:35 |
1:15 |
|
|
Times for a one-way trip are given as hours:minutes and assume an average
favorable current of one-half knot. |
|
|
The table above shows estimated trip times for each 5.5-mile leg. Times are calculated for a range of paddling speeds, do not include time for rest or breaks, and assume that kayakers have a favorable current. For simplicity, the average favorable current is estimated to be one-half knot throughout the harbor.
|
|
To select a date for this trip, search the Boston Harbor tide predictions for a low-tide time around midday. Low tide in Boston Harbor precedes low-water slack at the Graves by approximately 1.5 hours, but it is often easier to browse the tide times.
Once you have identified a candidate, use the tidal current calculator to predict the actual time of low-water slack at the Graves on that date. On May 17, the day selected as an example, low-water slack at the Graves occurs at 14:23, providing plenty of time for island tours and lunch before reaching the Graves.
To calculate a target launch time from Windmill Point, identify your group's paddling speed and determine how long it will take you to reach the Graves. Add in any planned rest stops, giving yourself plenty of time to enjoy the trip. Subtract this time from 14:23 to estimate your shove-off.
As a final check of trip timing, make sure that you will launch and land with favorable current in Hull Gut, using the tidal current predictions and estimated paddling times (plus rest stops) to be positive.
Places to Visit
During your trip, stop at Georges Island to tour Fort Warren. Obsolete when completed in 1847 and so never used for defense, the fort instead served as a training ground and prison during the Civil War.
Enjoyable not just for historical reasons, the fort also provides stunning views of the harbor from the ramparts. Note that Georges Island is the main ferry hub for the harbor islands, so expect company during the summer. Plan to spend about 45 minutes touring the fort and grounds.
|