David Burch Navigation Blog

We happen to have on consignment a C Plath sextant made for the Kriegsmarine in 1939 Germany. It is a prized collector's item, but we w...

  This is a place holder for soon to follow instructions on the use of polar wave spectra plots for understanding the seaway and for setting...

Background At present all ENC content and structure (internationally) are based on the IHO S-57 standard, and how these ENC should be displa...

May 31, 2026 update: added US states and bumped this note forward, A powerful function of qtVlm is its ability to show shapefiles in a very ...

The lunar distance method is a way to find UTC by measuring the angular distance between the moon and an adjacent body (sun, star or planet)...