NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Time Zone Designations
From: Stan K
Date: 2017 Jan 3, 16:46 -0500
From: Stan K
Date: 2017 Jan 3, 16:46 -0500
Just to stir the pot a little, in the StarPath book Hawaii by Sextant, by David Burch and Stephen Miller, a different scheme is proposed and recommended:
"...we use watch time (WT) to enter the logbook and record the sights, again just as we would do on the boat. Watch time in this case was Pacific Daylight Time, which is 7 h earlier than UTC, UTC = WT + 7h. This is the same throughout the voyage, which is the recommended system, as opposed to changing the ship's time during the voyage."
Stan
-----Original Message-----
From: Lu Abel <NoReply_LuAbel@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Tue, Jan 3, 2017 4:20 pm
Subject: [NavList] Re: Time Zone Designations
But why not keep all timepieces aboard a ship set to UT and simply hang signs noting the offset to local time? That way resetting the clock every time one crossed into a new time zone would not be required. And I suspect that setting the clock could cause it to be knocked off displaying accurate time.
From: Lu Abel <NoReply_LuAbel@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Tue, Jan 3, 2017 4:20 pm
Subject: [NavList] Re: Time Zone Designations
Frank wrote: "To this day, navigators are taught to record their sights in zone time,
presumably because time pieces were relatively rare decades ago, and it
was difficult (expensive) to have a separate watch or device displaying
UT."
I recall being on a US Navy supply ship a LONG time ago. Clocks around the ship had signs hung on them like "one hour slow." I was way to young at that point to understand UT or to determine which time zone the clocks were set to.
But why not keep all timepieces aboard a ship set to UT and simply hang signs noting the offset to local time? That way resetting the clock every time one crossed into a new time zone would not be required. And I suspect that setting the clock could cause it to be knocked off displaying accurate time.
I guess what I'm very politely saying is that I'm not sure I agree with Frank's argument -- and, in fact, it would make more sense to keep ship's clock(s) set to UT and simply note the offset to ZT rather than reset the clocks. So the custom of recording sight times in ZT continues to puzzle me at least -- as I faithfully record sight times in ZT as I have been taught...
