Originally Posted by capta
As there is no reason to use a sextant today, other than for fun, I would suggest you spend as little as possible. Spend your money on a back-up GPS. Using a sextant as a back up for GPS is quite unpractical. Taking sights on a small craft is no simple thing, it requires good enough weather to even get a sight, excellent math skills and a great deal of time much better spent sleeping on a crossing. Errors using a sextant are very easy to make (4 seconds of error in time is a mile error in position) and I don't care how proficient you get with one, you are still at the mercy of the weather. Between New Caledonia and Australia, in six days I was not able to get a single LOP until I had already passed through the Great Barrier Reef, not a relaxing experience.
One does not just whip out a sextant and snap a quick fix; it takes hours and skill to get enough good sights, reduce them to a LOP's and plot each LOP to get a fix.
I still have my sextants, though they are stored at my daughter's house. They are beautiful, near worthless bits of yesteryear, which I cannot bear to part with.
I agree with the above position.
And I share some of the opinions about the niceness of having a skill that can help one find ones way.
I love traditional things and traditional boats etc. I like sextants too.
I own the Astra sextant and used it as navigator on a yacht from Hawaii to San Francisco. At the time, the least expensive GPS was over $1,500 and they were new to the market. So I used sextant and later loran (now obsolete) when possible for confirmation or second source of fix. I used an expensive Swiss chronometer, but it turns out a cheap quartz watch was even more accurate. The Astra proved as accurate as much more expensive sextant that cost 4 times as much.
The super cheap brass sextants usually from India one sees on eBay are for decorative use, not for accurate navigation. Look nice on a shelf, but I would never trust them on a voyage, and would prefer one of the well made plastic ones over the eBay/Indian brass deco bookends.
Unfortunately, while the sextant was fun/challenging to use on the open sea, I also learned a lesson.
While getting closer to the California coast, we were in several days of dense fog (the ancient mariner's dread) and unable to get a fix. Sailing for days and nights into thick fog towards a dangerous shore and crossing vessel traffic lanes is a sure way to appreciate the anxiety that comes with not knowing precisely where you are, when knowing may make the difference between successful landfall or tragedy. Put simply, knowing where you are after a 2,500 nm offshore passage and as you approach a hazardous coast in the dark with limited visibility can be a matter of utmost concern. Dead reckoning can get you dead.
Sure, we knew that sooner or later we would hit dirt if we just kept sailing due east, but the question was, Where was the Gate?
Numerous ships including seven US Navy destroyers were lost due to navigational errors on the same coast we needed to find...in the fog. Here is a very good wiki article that tells the story of the worst peacetime disaster for the USN. Well worth reading. Also look at the aerial photo showing the SEVEN destroyers that hit the rocks!
Honda Point Disaster - Wikipedia, the free encyclopedia
One of the aspects of that tragedy was the commanding officer's refusal to use the fix reported derived from the electronic navigation device of the day, because he did not trust it. (Newfangled high tech device of its day).
While I admire the sextant, I will in the future carry two GPS units with me on any offshore or coastal runs. And extra batteries of course.
2. Reliability (in any weather)
3. Ease of use by any crew member
Also, I think the ease of use of the GPS allows more people to have the ability to get very accurate position and quickly, AND at anytime or in fog or bad weather.. something that was never common on boats before. Most old school mariners would never let anyone handle their expensive sextant, for fear of messing it up (creating error making), while today's handheld GPS units can easily be shared, handled, and used more frequently or even continuously. In fact I would make it a point to show my crew how to use my GPS, to give them a skill that could prove handy.
I hope these statements are helpful to someone.