Canadian Hydrographic Service
Central and Arctic Region

CA473034 - SUMMERLAND GROUP TO/A GRINDSTONE ISLAND

CABLES
The symbols for submarine and overhead cables do not differentiate between cables
conducting electric power, often at high voltages, and other types of utility cables.
Mariners are advised to exercise caution when passing under all overhead cables
and to avoid anchoring or conducting seabed operations in the vicinity of
submarine cables. The clearance of an overhead cable may differ from its charted 
value due to changes in atmospheric conditions, water levels and other factors.
For additional information, consult Notice No.16 in the Notices to Mariners,
Annual Edition and the appropriate volume of CHS Sailing Directions.

ST. LAWRENCE SEAWAY
For information regarding lock data, limiting vessel dimensions, and regulations governing 
the transit of vessels in the St Lawrence Seaway between the Port de Montral and Lake Erie, 
refer to the SEAWAY HANDBOOK of which a current copy must be carried on board all vessels 
transiting the Seaway.  A copy of the Seaway Handbook can be obtained from the St. Lawrence 
Seaway Management Corporation, Cornwall. 

 Fisheries and Oceans Canada 2017. Published by the Canadian Hydrographic Service. 
A licence is required from the Canadian Hydrographic Service (www.charts.gc.ca) to reproduce or distribute this work.
In addition, this product contains U.S. Government works or data, and is published with the authorization of the
Office of Coast Survey. No copyright is claimed by the United States Government under Title 17 U.S.C. with
regard to their works or data contained in this product. Therefore no license is required from the U.S. Office of
Coast Survey to reproduce or distribute U.S. data shown on this product.


