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:

Band 1
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.

Band 2 and 3
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.

ENC-USCHC Great Lakes Original Usage Band 2. Details above

Original

ENC-USCHC Great Lakes Revised Usage Band 2. Details above

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.

ENC-USCHC Great Lakes Original Usage Band 3. Details above and below

Original

ENC-USCHC Great Lakes Revised Usage Band 3. Details above and below

Revised

As a result the following ENCs will overlap:

Band 2 and 3
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

Band 4
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.

ENC-USCHC Great Lakes Original Usage Band 4-Lake Erie. Details above

Original

ENC-USCHC Great Lakes Revised Usage Band 4-Lake Erie. Details above

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.

ENC-USCHC Great Lakes Original Usage Band 4-Lake Ontario. Details above

Original

ENC-USCHC Great Lakes Revised Usage Band 4-Lake Ontario. Details above

Revised

Band 5
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.

ENC-USCHC Great Lakes Original Usage Band 5-Lake Ontario. Details above

Original

ENC-USCHC Great Lakes Revised Usage Band 5-Lake Ontario. Details above

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.

ENC-USCHC Great Lakes Original Usage Band 5-Lake Erie. Details above

Original

ENC-USCHC Great Lakes Revised Usage Band 5-Lake Erie. Details above

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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