NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Varuna -- Abandoned due to Loss of Power
From: Pete Solon Palmer
Date: 2017 Sep 10, 17:15 -0400
From: Pete Solon Palmer
Date: 2017 Sep 10, 17:15 -0400
<< there are now inexpensive apps available for iPads and their non-Apple equivalents that can display actual ENC charts. >>
Nobody can display ENC charts, because ENC is an archive format based on ISO 8211 and S-57. In all cases, the ENCs need to be converted to SENCs (System Electronic Nautical Chart) to be displayed. So every ENC Stakeholder has their own SENC format which is proprietary and closely guarded. Some systems convert the ENC to SENC on the fly and store the SENC internally. Other systems have tools to pre-convert the ENCs to SENCs, and others convert it and put the SENC on a cartridge. So from ECS to ECDIS systems, there isn't much difference in the process, but the results may be dramatically different.
<< Do not confuse recreational boat chartplotters and their charts with government issued ENC charts. >>
The warning letter I received from IHO was regarding inconsistencies of the government issued ENCs, from various different national HO agencies. So we have acknowledged discrepancies of the government base data, then it is converted by the display device according to its own interpretation, and we end up with a 2 tier game of Password. Be careful folks.
For those who are looking for the most reliable chart data, worldwide, the best way to get it is to go to the NGA website and download the Notices to Mariners and Light Lists for your area, and plot them on your chart.
Nobody can display ENC charts, because ENC is an archive format based on ISO 8211 and S-57. In all cases, the ENCs need to be converted to SENCs (System Electronic Nautical Chart) to be displayed. So every ENC Stakeholder has their own SENC format which is proprietary and closely guarded. Some systems convert the ENC to SENC on the fly and store the SENC internally. Other systems have tools to pre-convert the ENCs to SENCs, and others convert it and put the SENC on a cartridge. So from ECS to ECDIS systems, there isn't much difference in the process, but the results may be dramatically different.
<< Do not confuse recreational boat chartplotters and their charts with government issued ENC charts. >>
The warning letter I received from IHO was regarding inconsistencies of the government issued ENCs, from various different national HO agencies. So we have acknowledged discrepancies of the government base data, then it is converted by the display device according to its own interpretation, and we end up with a 2 tier game of Password. Be careful folks.
For those who are looking for the most reliable chart data, worldwide, the best way to get it is to go to the NGA website and download the Notices to Mariners and Light Lists for your area, and plot them on your chart.
Regards,
Pete
Pete
