Poll-Blue water. Is a Sextant Necessary?

[Rhapsody-NS27]

I'm thinking it would fall more into the "Fun to have" category. I've only seen them but not used one so I think it would be fun to have but also handy to learn Just in case something does require its use. I would like to get one some day.

[daddle]

Same question. Never answered. If one goes offshore without a sextant and then loses all other tools to acquire a fix how soon does death or disaster come?

[sailorboy1]

Originally Posted by Rhapsody-NS27

I've only seen them ............... I
would like to get one some day.

I've seen pictures of them. Maybe I will see one for real one day, like in a museum.

[Rhapsody-NS27]

Originally Posted by Don Lucas

I've seen pictures of them. Maybe I will see one for real one day, like in a museum.

The ones I saw were on display in a shop in Afghanistan. Not exactly a reliable source for navigation purposes on the water.

[Hudson Force]

Sextant, Slide Rule, RDF, LORAN, Astrolabe, Taff rail cannon, Lead line..........? What's next? I'm keeping a grip on my Pelorus!

[noelex 77]

Originally Posted by Pete7

If you were sailing across a large stretch of water say the Atlantic or Med and you suffered a lighting strike taking out GPS and Compass etc, could you bring your yacht to safety without a sextant?

BTW there is a thriving market in second hand sextants in the UK, sold my Mk 15 Davis on YBW within a couple of hours of posting the advert.

Pete

There are really two questions here:

If you store a backup GPS unit in faraday cage how like key is it to survive a lightening strike. It is any important question without a lot of hard facts.
My best conclusion is that a GPS unit inside a reasonable faraday cage is likely to survive all but a severe lightning strike.
In a severe lightning strike there will be structural problems with the boat that renders the loss of navigational information a more minor problem.


The second question is if you did loose all navigational data could you make a safe landfall?
In most cases I believe the answer is Yes. You would have to sail away from hazards and therefore may not end up at your original destination and/or adopt techniques such as heaving too at night.
Steering by the sun and stars (assuming your compass has been damaged) would be crude, but would be adequate in most cases.

The challenges with these sort of problems would be severe, but less than other disasters such as collision, fire, loss of rudder etc.

As a piece of safety equipment does the sextant justify the cost (and effort to learn and remain proficient)?. Would the money be better spent say on survival suits, a second life raft more storm equipment etc?

[barnakiel]

Sextant is just another prosthesis for proper seamanship ;-)))

b.

[bobconnie]

We have all the stuff most cruiseing folks have ! a loptop with navagation program and world wide charts, and couple of simple gps hand helds battery operated. And Lots and Lots of paper charts ! I still use a noonsite with my old Plath sextant, and a planet or start site sometimes ! and log and chart all of the info from all of these things! gives me something to ck against Connies laptop. And gives me a little practice and keeps my brain sharp with the simple math! I am easyly pleased! LOL and if things EVER go to Hell Im ready to go just like I was 40 yrs ago before all this stuff was even thought of !! Connie and I sailed the whole Pacific rim with only paper charts and a sextant and a nautical almanac
it worked then and would work now ! but I admit I like my hand held ! Still seems like majic to me LOL All I can say is it's really a fun way to keep tract of your possition ! But not really nessary ! hell ya can sail west or east and get somewhere sooner or later without anything !!But who would want to do that ?? not me if I can help it ! so I carry and use my sextant as much as I can, just for the heck of it !!!

[westsail374]

Here's a possible issue:

Many weapons that could be used by terrorists for stand-off attacks use GPS for guidance. Similarly, some aircraft that may be used by hostiles use GPS for the same purpose. That's why the Feds have the capability to shut down the system at any time, with no notice whatsoever.

It's a dangerous world out there. One reason some folks sail is to get away from all the bad news. But if one relies solely on GPS for navigation, the bad news could end up biting ya on the rear end at a most inconvenient time.

The bottom line for me at least is that I believe that possession of all instruments needed for independent offshore navigation is not a luxury or a charming anachronism - it is the act of a prudent mariner.

I have a '50's era Plath sextent , a Davis plastic backup, a chronometer, a backup, paper charts - large and small scale (older but still serviceable), and appropriate publications (at least HO 249).

Maybe the Feds will never need to turn off GPS.

But if they do, I want to be ready.

[Ex-Calif]

Hmmm - I voted save your money but would have preferred, "Spend you money on everything else first."

So what is the longest passage? With GPS the furthest you can be from landfall is halfway. You note your fix every 2-4 hours. So when the entire GPS system fails you still know where you are.

Next - presuming the GPS failure is permanent (highly unlikely) - you need to make landfall without a sextant or skills.

Small islands are hard to hit (ask Amelia Earhart - although she did not have an updated electronic fix) so one could decide to head for the larger landmasses which are hard to miss.

The skills of plotting a ded reckoning course from a known fix are more important, IMHO, than knowing how to use a sextant (these days).

Finally, let's say you decided to press on to Hawaii or Fiji rather than heading back to the American coastline ( a target I hope we agree just about anyone can hit.

What about an RDF? If I get within AM radio coverage of Hawaii, there are pretty cheap RDF units that can immediately provide a bearing to any AM station.

There are plenty of threads around here where the opposing views of Sextant vs. GPS are haggled ad nauseum.

What about a discussion of, "How to make landfall when the GPS fails and you don't have a sextant on board?"

Learning alternate skills to celestial may be more fun than doggedly repeating that you will die if you don't know celestial nav.

[goboatingnow]

Originally Posted by westsail374

Here's a possible issue:

Many weapons that could be used by terrorists for stand-off attacks use GPS for guidance. Similarly, some aircraft that may be used by hostiles use GPS for the same purpose. That's why the Feds have the capability to shut down the system at any time, with no notice whatsoever.

It's a dangerous world out there. One reason some folks sail is to get away from all the bad news. But if one relies solely on GPS for navigation, the bad news could end up biting ya on the rear end at a most inconvenient time.

The bottom line for me at least is that I believe that possession of all instruments needed for independent offshore navigation is not a luxury or a charming anachronism - it is the act of a prudent mariner.

I have a '50's era Plath sextent , a Davis plastic backup, a chronometer, a backup, paper charts - large and small scale (older but still serviceable), and appropriate publications (at least HO 249).

Maybe the Feds will never need to turn off GPS.

But if they do, I want to be ready.

Firstly GPS ( and glonass, and hopefully Galileo , then the Chinese gnss etc) will never be turned off. " we" need it more then the baddies do.

Having said that I'm a student of traditional nav methods , so I have a sextant , and even a lovely Walker trailing log. But a sextant is like a GPS it needs support tools. The fact is any competent sailor can latitude sail and reach ones destination ( or at least land ). A sextant is a tool , like GPS. It has failure modes too. Shackletons great luck was his captain had a few pages of his nautical almanac, not that he had a sextant.


Dave

[IslandHopper]

Is a Sextant Necessary?

No, but then neither is a GPS.....

I carry and use all....

[Adelie]

Originally Posted by noelex 77

Has a sextant and the ability to use it become no longer necessary for a blue water sailing boat.
Sadly I think the answer is yes. I wish it was not so. The sextant is a wonderful instrument to use and it is immensely satisfying, but is it necessary?

...

The GPS system is more robust than it was 20 years ago. With cheap GPS units its feasible to have multiple backups and keep some of these sealed with their own power supply and protected by a faraday cage.

So is a sextant and the ability to use it essential for for blue water cruising?

Is it essential for everybody? NO.

Is it essential for you? That depends on your feelings and decisions about how to deal with risks.

Complete loss of GPS is a low likelihood but moderate to high consequence event.

Would a metal box completely protect your backups from a lightning strike; probably better than 50% but less than 90%.

How about the sinking of your boat? That is a low likelihood but high or very high consequence event. About 1/3 of folks in another thread said they wouldn't carry a liferaft. Keep in mind that most or all of them indicted they would use their dinghy if the boat sank, so it wasn't that they didn't have an alternative.

How about dealing with a fire on-board? Are the perceived likelihood and consequences high enough that you would forego propane stove fuel for alcohol? How about having a gas engine on-board instead of a diesel?

I seem to have expanded the topic quite a bit here. We now return you to your on-going thread.

[rebel heart]

If people spent as much time with a sextant as they did dicking around with their chart plotters and "convenience" items, they'd know celestial navigation. It's funny to watch people spend tons of money and time on stuff in an effort to make things easier.

Partially for me it's a safety item, but also for me it's an aspect of seamanship. You don't need to know how to whip your own lines either: you can just have them done for you. But that and other sailing arts make up the canon of seamanship. When my daughter asks me about the sky I can rattle off all the planets and constellations without needing to look at my friggin phone.

I'm over trying to convince anyone of anything. If you have passengers onboard and you don't know celestial navigation (or other non-electric means) you should shake everyone's hand and make sure they know you're a lightning bolt away from having no clue where the hell you're going.

[rebel heart]

Originally Posted by noelex 77

If you consider a sextant essential, then you are probably going to carry at least small scale paper charts a mechanical chronometer and perhaps a towed, mechanical log.
Any position can be readily plotted on an electronic chart, but it would take a catastrophic event to disable the multitude of GPS satellites and some of the scenarios, such as large EMP, could wipe out even protected electronics.

Personally I consider the risk of this sort of event as very low and in most cases landfall could be made safely anyway.
There are plenty of other, more serious, potential problems such as hitting a container, sinking, and the life raft failing, to name just one.

The *only* reason people don't carry sextants or use them is total laziness. You can buy cheap ones for next to nothing, certainly a tiny fraction of the amount of money folks are dumping into BS they don't need on their boats.

It's not about the money, it's about their ever-so-precious time which simply cannot be wasted on such a grueling effort as learning some basic friggin math.

I understand why people don't lift weights: it's hard. It requires constant engagement and commitment, basically day in and day out. You'll spend months learning the techniques and years learning advanced stuff. The rewards are worth it, but it's a total commitment and most people honestly do the bare minimum to get by.

Learning celestial navigation is like riding a bicycle. Sure, it helps if you do it every now and then to stay fresh but it's not like you need to figure it out all over again each time. Shoot a damn noon site when you're otherwise sitting in the cockpit playing angry birds.