A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robin Stuart
Date: 2017 Feb 15, 05:29 -0800
From Bowditch's glossary: 2. The point at which reckoning of a voyage begins. It is usually established by bearings of prominent landmarks as the vessel clears a harbor and proceeds to sea. When a navigator establishes this point, he is said to take departure.
I also intially thought the reference to "chronometers" was telling but have since changed my view. We know that the Endurance carried 24 chronometers and so I expect that Worsley would be in the habit of talking about "rating his chronometers" in the plural,