Davis Sextants

[Stingo]

The mark 15 and mark 25, from what I can gather, were both very successful, as reflected by the prices they command on ebay. The mark 20 occassionally comes up and sells for significantly less than the other two models.

Any ideas why this might be?

Thanks in advance.

 

[lustyd]

People do their research and decide the 15 is the one to go for since they don't need the "better" one. This means that all the bidding is on the cheaper model as there isn't demand for the other. I doubt there's anything nefarious, just most people don't think to look for the one they "can't afford" on ebay etc.

 

[Stingo]

Surely then they'd be going for the Mark 3?

 

[lustyd]

FWIW I bought the 15 recently and it was so badly adjusted I nearly took it back (never used one before). If you get one spend some time to twiddle the screws! I feel they probably do this on purpose to force you to adjust it at least once. Great device, currently worthless as I've not seen the sky since purchase

 

[lustyd]

The 15 and 20 are "proper" ones. The 3 looks like a learning tool only. Very few people will know what they need when buying so go for the cheap proper one. This is the whole reason they make a range, so you're happy with the one in the middle!

 

[Norman_E]

When a very good sailing friend of mine died I was given his Mk15. I also have an Ebbco sextant. The MK15 is certainly the better of the two.

 

[laika]

FWIW I bought the 15 recently and it was so badly adjusted I nearly took it back (never used one before).

You just get into the habit of adjusting it every time you take it out of the box. Only takes a minute and ideal for people like me who if they had a metal one which didn't need regular adjustment would need to spend ages remembering how to do it. I wasn't familiar with the 20 because it doesn't seem to have been a current model since before I bought my mk 15 12 years ago. That might be one reason it's not so popular? Am I right in thinking it's basically a 25 but split view? I can't say not having the 25's light on the 15 has been a problem but if the 20 is cheaper than the 15 why wouldn't you?

Whenever the mk 15 comes up I give the same positive reviews and say people who say you can't do star sights with a plastic sextant are talking nonsense. They seem to be *way* over-priced in the UK though. I got mine new in the US for under £100. I note they're now $133: more expensive since our currency fell off a cliff 4 years ago but still cheap. Shame no-one is travelling at the moment and shipping + VAT will crank up the cost.
Davis Mark 15 Master Sextant - Celestaire, Inc.

 

[Spirit (of Glenans)]

You just get into the habit of adjusting it every time you take it out of the box. Only takes a minute and ideal for people like me who if they had a metal one which didn't need regular adjustment would need to spend ages remembering how to do it. I wasn't familiar with the 20 because it doesn't seem to have been a current model since before I bought my mk 15 12 years ago. That might be one reason it's not so popular? Am I right in thinking it's basically a 25 but split view? I can't say not having the 25's light on the 15 has been a problem but if the 20 is cheaper than the 15 why wouldn't you?

Whenever the mk 15 comes up I give the same positive reviews and say people who say you can't do star sights with a plastic sextant are talking nonsense. They seem to be *way* over-priced in the UK though. I got mine new in the US for under £100. I note they're now $133: more expensive since our currency fell off a cliff 4 years ago but still cheap. Shame no-one is travelling at the moment and shipping + VAT will crank up the cost.
Davis Mark 15 Master Sextant - Celestaire, Inc.

The cliff looms again on 1 Jan?

 

[Norman_E]

There is a MK 15 on ebay now, so far it has no bids, and a starting price of £49. Its in its box, and although I have no idea of condition it looks just as good as mine in the only photo. Davis Master Mk 15 Sextant | eBay

 

[Stemar]

I could see taking one as ultimate backup on a transoceanic voyage, but in these days of chart plotters, does anyone actually use a sextant for serious navigation?

 

[AndrewB]

I could see taking one as ultimate backup on a transoceanic voyage, but in these days of chart plotters, does anyone actually use a sextant for serious navigation?

My Mark 15 got me to the Canary Islands 25 years ago. In time the plastic sprockets wore increasing the backlash and making the instrument too inaccurate for serious use. Something to watch out for if buying second hand.

 

[ithet]

I could see taking one as ultimate backup on a transoceanic voyage, but in these days of chart plotters, does anyone actually use a sextant for serious navigation?

As Tom Cunliffe pointed out, you need a GPS to provide the accurate time signal

 

[neil_s]

Davis did used to do a vernier model - was that the Mark 20?

As Tom Cunliffe pointed out, you need a GPS to provide the accurate time signal

My Casio chrono loses 1 second per week.

 

[Sandy]

I have a second hand MK 25 bought second hand, preloved in modern lingo, by several members of this forum. With little practice I can get within 10 NM of my GPS position. I am not in the school of nanometre precision when it comes to spotting land at sea.

 

[Yellow Ballad]

I bought an Astra iiib for a similar price to what the Davis 15 is going for on ebay so might be worth looking out for other brands, I must admit I did strike lucky, I've not seen one go for that price since.

I average about 5 miles off at the moment but I think I need to hone my sights but I think I'm being a bit eagar judging when it's on the horizon. Practice I suppose.

I've not done a passage long enough to really use astro but why not?!?

 

[Skylark]

I bought an Astra iiib for a similar price to what the Davis 15 is going for on ebay so might be worth looking out for other brands, I must admit I did strike lucky, I've not seen one go for that price since.

I average about 5 miles off at the moment but I think I need to hone my sights but I think I'm being a bit eagar judging when it's on the horizon. Practice I suppose.

I've not done a passage long enough to really use astro but why not?!?

Sounds like you did well to buy an Astra for the price of a Davis. Setting up an eBay search and a degree of patience seems appropriate.

The purpose of establishing a running fix is firstly to ensure that you are not close to a danger and secondly to help shape your course. 5M different to a GPS is very good.

Judging the horizon is part of the skill, especially in an Atlantic swell. I’m assuming that you’re taking half a dozen sights over 10 minutes or so, plotting them, drawing a best fit straight line between them and choosing a time and Hs from the line?

 

[Yellow Ballad]

Judging the horizon is part of the skill, especially in an Atlantic swell. I’m assuming that you’re taking half a dozen sights over 10 minutes or so, plotting them, drawing a best fit straight line between them and choosing a time and Hs from the line?

I'm just using an artificial horizon at the moment so not running fix, managed to get a davis AH recently which has made a big difference minimising ripples. Probably only taken a dozen sights but it's the workings I wanted to crack, I imagine taking sights on a swell and advancing sights will be the next challenge as well as identifying stars and planets.

Some of my LOPs have been bang through my gps location but the intersects have put me off a bit but I'll like to try and get some closer fixes using the AH but at the end of the day it's pretty mindblowing to me at least I can find outwhere I am using a couple of books and a sextant.

But I'm glad I've learnt/learning the art, it's good to keep the grey matter working.

 

[KompetentKrew]

I bought an Astra iiib for a similar price to what the Davis 15 is going for on ebay so might be worth looking out for other brands, I must admit I did strike lucky, I've not seen one go for that price since.

Yes, I paid £105 for a Freiberger Jena which I have still not yet used.

I was checking my eBay saved searches daily for a long time before it came up though - I figure if I spent only 5 minutes a day doing that (a conservative estimate) then that's 25 hours a year I paid for only a handful of bargains!

 

[Beneteau381]

You just get into the habit of adjusting it every time you take it out of the box. Only takes a minute and ideal for people like me who if they had a metal one which didn't need regular adjustment would need to spend ages remembering how to do it. I wasn't familiar with the 20 because it doesn't seem to have been a current model since before I bought my mk 15 12 years ago. That might be one reason it's not so popular? Am I right in thinking it's basically a 25 but split view? I can't say not having the 25's light on the 15 has been a problem but if the 20 is cheaper than the 15 why wouldn't you?

Whenever the mk 15 comes up I give the same positive reviews and say people who say you can't do star sights with a plastic sextant are talking nonsense. They seem to be *way* over-priced in the UK though. I got mine new in the US for under £100. I note they're now $133: more expensive since our currency fell off a cliff 4 years ago but still cheap. Shame no-one is travelling at the moment and shipping + VAT will crank up the cost.
Davis Mark 15 Master Sextant - Celestaire, Inc.

A kind forumite sold me the cheap one, the mirror adjusting screws are mild steel, they sieze with rust. I carefully sawed them out and replaced with SS allen machine screws. It now keeps its "tune"

 

[neil_s]

I have just moved up from an Ebbco - here's a tip for the plastic sextant users that worked for me. When you take a sight, do 5 quick 'shots' and average the results.