A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robert Eno
Date: 2015 Feb 3, 12:39 -0700
Thanks for the response Paul. Now I wish I had not gotten rid of that C&P bubble attachment so quickly.
As to my expertise, I appreciate your vote of confidence but I sure do not consider myself to be an expert on these matters. “Seasoned” perhaps, but I know that there are a lot of folks on the list who have forgotten more than I ever knew.
The early C.Plath bubble attachment is, in my opinion, the best marine sextant bubble attachment ever devised. I have used a wide range of bubble attachments so I base my opinion on hard-won experience.
I agree with Paul on the subsequent generations of C.Plath bubble attachments and especially the last iteration. And the quality and performance of the latter generation of C.Plath bubble attachments was not at all commensurate with the price tag. From what I understand, as the years advanced and as celestial started to compete (unsuccessfully) with electronics, C.Plath in an effort to stay solvent, cut production costs by manufacturing simpler devices. Anyone who has had a good look at the Plath “Firefly” will attest to its complexity and flawless workmanship. Like all old instruments, they also lent themselves to repair, provided that one had the proper tools and know-how. It is clear that this device took some effort to manufacture but with a shrinking market, its demise was inevitable.
But now Paul’s observations (no pun intended) on the C&P is creating some angst in me. I perhaps should have given it more of an effort. At the time though, I figured out how to repair my C.Plath firefly so it was a matter of cashing in on $800 worth of C&P bubble horizon that I was not going to use and that frustrated me. In hindsight, I should have hung on to it.
Thanks for that info Paul.
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Paul Saffo
Sent: February-03-15 11:47 AM
Subject: [NavList] Re: Plath bubble sextant on ebay (C&P versus Plath)
- First of all, when it comes to bubble horizons, I always defer to you, Robert! (For everyone else, I am serious -- Robert knows more about Plath AFs than anyone I know and I would always ask him first if I had AH questions). Here are my thoughts:
- The ideal AF has a dimmable light source, an adjustable bubble and a well-designed reticle. Dimmable matters bec one needs diff light levels for day/dusk/night sights. Adjustable matters bec of diameter of target. A well-designed reticle (I like concentric circles w/crosshairs) will help compensate if the bubble is not adjustable.
- I believe that the early Plath "Firefly" AH is thus the best option bec it has both an adjustable bubble and dimmable light source. Regrettably I have never been able to get my hands on one, so hope others with experience will add their comments.
- the next generation Plath AH has a dimmable light source that draws power from the sextant's batteries, but no bubble adjustment. Its reticle is a simple crosshair. Its performance is acceptable, but I miss having an adjustable bubble esp as the reticle leaves much to be desired.
- the third gen Plath AH has a non-dimmable (red LED) light source powered by internal batteries. Bubble is not adjustable. Reticle is an octothorpe pattern. This seems to be the worst of all options. I'd love to get rid of it but cannot in good conscience sell it to anyone because its performance leaves so much to be desired.
- The C&P AH has a dimmable light source powered off the sextant, but no adjustable bubble. Its reticle is cut so that it is much easier to determine the bubble center than on the two Plath AHs I have. I thus find it a satisfactory AH, but expect that a Firefly would be superior.
- The modified A10 is a really terrific option as it has both dimmable light and adjustable bubble. And if one is lucky, they can be had for considerably less than a Plath or C&P. Mine was modified by Bill Morris, so am hoping he will step in and talk about his experience as this is a really nifty option if one can get an A10 capsule
Finally, a qualification about my experience. All of my use has been in a backyard or from the shore. I cannot imagine using an AH on the water on anything smaller than an aircraft carrier. AHs are fussy, sensitive accessories and hard enough to use when one is comfortably set up with a table and a cup of tea on terra firma. Using them while bobbing among the waves strikes me as being like trying to thread a needle while giggling...