A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Art Leung
Date: 2021 Dec 3, 06:06 -0800
Hello, Howard - you wrote: "Very keen to get back in the driving seat with astro though bit sad it cannot be used at night only at dawn, dusk and day."
I live in a forest and use a Kollsman periscopic sextant most nights when the skies are clear. I usually take the shots well after sunset as it is easier to pull out the dimmer stars in the darker sky. I strap the sextant onto a leveling tripod (aka "bowl tripod") - while I have a custom made mount, it isn't strictly necessary.
I get very good fixes - almost always inside of 2nm using my trusty Polhemus and frequently better when I take the time to use Pub229.
The periscopic sextants (Kollsman and the RAF equivalents) are commonly found on eBay and they hold their bubbles well. I have repaired a couple of bubble units (I am writing a short description of that process that I hope Bill Morris will post on his excellent blog sextantbook.com). Not all of the instruments on eBay look serviceable but I've had good luck with the ones that I've picked up. Bill also has an article on replacing a pellicle should it be necessary - I've done it and it works nicely.
For power, I use a DC-DC converter and USB battery.
If you wish to use a nautical sextant away from a real horizon, I use a carpenter's laser level and a couple of tripods. Again, this lets me take shots any time of dark. It's more equipment intensive compared to a pan of water, of course, but I can shoot stars at any altitude I want as easily as one would with a real horizon. It takes me about 2 minutes to set everything up for a shot, so it's not unreasonably slow.
If you have any questions on how either of my setups work, I'd be happy to answer them.