4 ms·
If you buy maps from the USGS [0], they have the magnetic north and true north indicated on them so you can adjust your compass. I didn't realize how rapidly my
by jonahhorowitz 8y ago
If you buy maps from the USGS [0], they have the magnetic north and true north indicated on them so you can adjust your compass. I didn't realize how rapidly my maps got out of date.
[0] - https://www.usgs.gov/products/maps/topo-maps https://www.usgs.gov/products/maps/topo-maps
- emmelaich 8y agoFor naviagtion, charts are updated via [0] Notices to Mariners . It is of course the responsibility of the mariner to mark/attach the notice to the chart. [0] https://en.wikipedia.org/wiki/Notice_to_mariners https://en.wikipedia.org/wiki/Notice_to_mariners