Astra iiB

[paulajayne]

Has anyone got a source for lens caps for the Astra IIIb Sextant please?

I am surprised that it does not come with them and a neck strap as standard.

Thanks

[bletso]

I don't see these options on the celestaire website https://www.celestaire.com You might contact them direct. They are usually quick to respond.

[paulajayne]

Thanks - Yes I had looked at their web site.

I shall try an Email to them.

[svHyLyte]

Originally Posted by paulajayne

Has anyone got a source for lens caps for the Astra IIIb Sextant please?

I am surprised that it does not come with them and a neck strap as standard.

Thanks

Paul--

Lens caps are unusual in as much as the instrument is normally only removed from its case when it's needed and quickly returned thereto once used (after being wiped down) and rarely, if ever, out of one's hands twixt the two. Never the less, simply measure the outside diameter of the particular telescope you're Sextant is fitted with and you can certainly find lens caps that will fit via an internet search.

Regarding neck straps, when using our Sextant, I do clip a lanyard to the hand grip post on the offhand side of the frame against the possibility that I loose my grip on the device in a rough moment but, thus far (in 29 years) that has never happened. In very rough conditions, its difficult or impossible to get a useful sight (although many will certainly jump in to disagree with that comment) hence one, normally doesn't even try. One cannot simply hang the device around ones neck as one might do with Binoculars or a hand bearing compass as even a slight bump can, and probably will, knock the mirrors out of alignment making any subsequent sights, without realignment, useless. Again, one rarely ever releases ones grip on the device while its out of its case save, perhaps, when it's stood on the nav-table (fitted, of course, with proper fiddles to prevent items from going adrift) for a few moments for reference of the reading while working a sight. Then it's back, again, in its case.

FWIW...

[bletso]

Good practical observations.

[a64pilot]

OK stupid question, are there many Celestial Nav course being taught?
I have a Sextant, and other than a conversation piece or paperweight, its not much use to me, plan had been once we go that surely I will have spare time, enough anyway to learn to use the thing.
Until then though my weekends have been taken up with getting the boat ready

[bletso]

Check your local United States Power Squadron for one. The closest one to you is the Muskogee Squadron - contact gregmsmith@knology.net

[a64pilot]

Originally Posted by bletso

Check your local United States Power Squadron for one. The closest one to you is the Muskogee Squadron - contact gregmsmith@knology.net

Thanks I'll wait until we are in Brunswick, we will spend next years Hurricane season there as our Daughter will be attending the local College.
I should be able to find something around there or Savannah

[El Pinguino]

Originally Posted by a64pilot

OK stupid question, are there many Celestial Nav course being taught?
I have a Sextant, and other than a conversation piece or paperweight, its not much use to me, plan had been once we go that surely I will have spare time, enough anyway to learn to use the thing.
Until then though my weekends have been taken up with getting the boat ready

This may keep you out of mischief for a while... http://www.cruisersforum.com/forums/...ff-144799.html

Download it from Dropbox

[bletso]

If you are in Savanna, there is a local squadron there. Home and the contact is Ronald Lynch at navyret88@comcast.net

[a64pilot]

Originally Posted by bletso

If you are in Savanna, there is a local squadron there. Home and the contact is Ronald Lynch at navyret88@comcast.net

Not yet, but I will be within striking distance by car

[svHyLyte]

Celestial Navigation really isn't particularly difficult in and of itself. It is getting good sights; and, having good time keeping equipment that makes (or breaks) the process. While one can use all of the navigational stars, the moon and the sun, sun sights are generally the easiest and can give one nearly all the information one needs to get from A -> B, albeit without great precision. Never-the-less, sun sights are a good, relatively easy, starting point.

An excellent reference in a somewhat "cook book" sense/methodology is Mary Blewitt's "Celestial Navigation for Yachtsmen", first published in 1967 (which I used/learned from at the time). The 13th Edition, updated in cooperation with Adlard Coles (see--click on--here). Is very easy reading with good, clear, explanations. There are, of course, more comprehensive treatments of the subject with many of the better books being offered by Celestaire . Prior to the advent of LORAN equipment priced for recreational use, Celestial was a necessary skill for off-shore passages of any length (and it had the collateral benefit of keeping distant shores free of clutter!).

FWIW...

[Scott Berg]

There are a few other great texts as well; I like 'A Star to Steer Her By' by Edward Bergin https://www.amazon.com/Star-Steer-He...o+steer+her+by As well as Celestial Navigation in the GPS Age by John Karl https://www.amazon.com/Celestial-Nav...ords=john+karl and Simple Celestial by Chris Kreitlein https://www.amazon.com/Simple-Celest...hris+kreitlein

All provide a good, form based walk through the procedures of taking, reducing, and plotting a sight/LOP/Fix. It's a skill we should all have who venture offshore. It both keeps your 'head in the game' and provides failsafe backup when the black boxes don't work