Great Lakes
To comply with internationally agreed practices, Canada and the United States of America have agreed to eliminate overlapping coverage of Electronic Navigation Charts (ENCs). This new ENC coverage scheme will result in each country adjusting its areas of coverage to ensure only one country's ENC would be available for any given area at a particular scale.
These changes in the Great Lakes come into effect at 00:00 hours Coordinated Universal Time (UTC), on 22 February, 2013.
The graphical representations of the ENC coverage "before" and "after" and lists of the official revised ENC limits as agreed upon by Canada and the United States are presented below.
Note: The graphical representations only depict affected areas and their products.
The following represents the ENCs that are affected by this project:
| Cell Name | Producing Authority | Title | Band | Scale |
|---|---|---|---|---|
| CA173289 | CA | Lake Superior/Lac Superior | 1 | 600,000 |
As CA173289 is the same scale as US3MI79M, Canada will cancel CA173289 in favor of US3MI79M, which will become US2MI79M.
| Cell Name | Producing Authority | Title | Band | Scale |
|---|---|---|---|---|
| CA273095 | CA | Lake Huron/Lac Huron | 2 | 400,000 |
| CA273097 | CA | Georgian Bay/Baie Georgian | 2 | 200,000 |
| CA273094 | CA | Lake Erie/Lac Erie | 2 | 400,000 |
| CA273096 | CA | Lake Ontario/Lac Ontario | 2 | 400,000 |
| US2EC03M | US | Cape Sable | 2 | 1,200,000 |
| US3MI79M | US | Lake Superior | 3 | 600,000 |
| US3MI80M | US | North End of Lake Michigan | 3 | 240,000 |
| US3MI60M | US | Lake Huron | 3 | 500,000 |
| US3OH03M | US | Lake Erie | 3 | 400,000 |
| US3NY21M | US | Lake Ontario Metric | 3 | 400,000 |
Within the Great Lakes region the majority of the ENC overlaps are at the Band 3 navigation purpose. This is a result of Canada and the United States Canada utilizing different scale ranges for their ENC navigation purpose. The following graphic shows the current overlap at Band 3 between the United States and Canada.
Original
Revised
As the Great Lakes region is a relatively isolated body of water, the United States will move its Band 3 ENCs to Band 2 to better align with the Canadian ENCs at that same scale. This will eliminate any overlaps at Band 3 - however, it will cause new overlaps at Band 2. However, these new overlaps will be between ENCs that represent similar coverage and similar scale.
As a result of this change, all navigation purpose 3 overlaps are eliminated and we are dealing with newly created overlaps at navigation purpose 2.
Original
Revised
As a result the following ENCs will overlap:
| Cell Name | Producing Authority | Title | Band | Scale |
|---|---|---|---|---|
| CA273095 | CA | Lake Huron/Lac Huron | 2 | 400,000 |
| US3MI60M | US | Lake Huron | 3 | 500,000 |
| CA273097 | CA | Georgian Bay/Baie Georgian | 2 | 200,000 |
| CA273094 | CA | Lake Erie/Lac Erie | 2 | 400,000 |
| US3OH03M | US | Lake Erie | 3 | 400,000 |
| CA273096 | CA | Lake Ontario/Lac Ontario | 2 | 400,000 |
| US3NY21M | US | Lake Ontario Metric | 3 | 400,000 |
The United States will retain responsibility for Lake Superior and Lake Huron and Canada will retain responsibility for Lake Ontario and Erie.
As a Result the United States will cancel US3MI60M and re-issue it as US2MI60M with the revised extents cut back to account for CA273097 (Georgian Bay) and Canada will cancel CA273095.
The United States will cancel US3OH03M and US3NY21M
| Cell Name | Producing Authority | Title | Band | Scale |
|---|---|---|---|---|
| CA473305 | CA | Long Point Bay | 4 | 50,000 |
| US4NY38M | US | Buffalo to Erie | 4 | 120,000 |
| CA473277 | CA | Upper Gap to Telegraph Narrows | 4 | 30,000 |
| CA473276 | CA | Lower Gap to Adolphus Reach | 4 | 30,000 |
| CA473036 | CA | Carleton Island to Charity Shoal | 4 | 30,000 |
| CA473025 | CA | Grindstone Island to Carleton Island | 4 | 25,000 |
| US4NY20M CA473034 |
US CA |
Lake Ontario Clayton Summerland Group to Grindston Island |
4 4 |
80,000 25,000 |
The first overlap in Band 4 occurs between US4NY38M and CA473305 in Lake Erie.
As a result, the United States will cut back US5NY38M to the extents of CA473305 due to coverage being in Canadian waters.
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Revised
The next set of overlaps in Band 4 occurs in Lake Ontario between US4NY20M and CA473276, CA473036 and CA473025.
The United States will cut back US4NY20M to the extents of CA473276, CA473036, and CA473025 due to coverage being in Canadian Waters and CHS producing a better scale product.
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Revised
| Cell Name | Producing Authority | Title | Band | Scale |
|---|---|---|---|---|
| CA573012 | CA | Lower Niagara River & Approaches | 5 | 20,000 |
| US5NY31M CA573010 |
US CA |
Lower Niagara River Welland Canal |
5 5 |
30,000 15,000 |
| CA573385 | CA | Twyning Island Bridge | 5 | 10,000 |
| US5MI62M | US | St. Mary's River, Lake Numuscong to Sault Ste Marie, Including Lake George | 5 | 40,000 |
| US5OH10M | US | Islands in Lake Erie | 5 | 40,000 |
| CA573326 | CA | West Dock | 5 | 4,000 |
| CA573099 | CA | Scudder | 5 | 3,000 |
The next set of overlaps occurs in Band 5 in the vicinity of Niagara Falls. US5NY31M overlaps with CA573012 and CA573010.
Canada will cancel CA573012 in favor of US5NY31M and the United States will cut back the extents of US5NY31M to the extents of CA573010.
Original
Revised
The next set of overlaps occurs in the vicinity of Sandusky, Ohio on Lake Erie. US5OH10M overlaps with US5OH12M and CA573326 and CA573099.
Canada will move CA573326 and CA573099 to Band 6 and cancel the Band 5 coverage and the US will eliminate its internal overlap with US5OH12M.
Original
Revised
The final set of overlaps occurs in the Upper Peninsula region of Michigan. US5MI62M overlaps with CA573385.
As a result the United States will cut out a hole in US5MI62M for CA573385.
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