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 9, 13:39 -0400
From: Pete Solon Palmer
Date: 2017 Sep 9, 13:39 -0400
Dave C wrote:
<< chart plotters that allow the boat occupant to specify a route from A to B and the system will (or claims to) drive the boat safely around rocks and reefs >>
Be careful when using this type of feature. Situational Awareness is still very important. I received a letter from the IHO, a couple of years ago, warning that this type of function can fail due to the inconsistency of how objects such as rocks, reefs and obstructions are encoded in ENC charts from various HO agencies around the world. Everyone that officially supports ENC charts in their product (ENC Stakeholders) would have received the same letter.
I elected not to include such a feature in my chart plotter because it would require too much of the computer resources. Most ENC chart cells are mostly made up of land and land area polygons. These polygons are big with thousands of sides, so to continuously poll all these polygons, looking for obstructions ahead is sure to keep your computer very busy.
The chart plotter makers (including ECDIS) are racing to display the fanciest features at boat shows, when they should be racing to produce the most reliable product.
<< chart plotters that allow the boat occupant to specify a route from A to B and the system will (or claims to) drive the boat safely around rocks and reefs >>
Be careful when using this type of feature. Situational Awareness is still very important. I received a letter from the IHO, a couple of years ago, warning that this type of function can fail due to the inconsistency of how objects such as rocks, reefs and obstructions are encoded in ENC charts from various HO agencies around the world. Everyone that officially supports ENC charts in their product (ENC Stakeholders) would have received the same letter.
I elected not to include such a feature in my chart plotter because it would require too much of the computer resources. Most ENC chart cells are mostly made up of land and land area polygons. These polygons are big with thousands of sides, so to continuously poll all these polygons, looking for obstructions ahead is sure to keep your computer very busy.
The chart plotter makers (including ECDIS) are racing to display the fanciest features at boat shows, when they should be racing to produce the most reliable product.
Regards,
Pete Palmer
Pete Palmer
