CELNAV is actually a thing. It can be completely automated and computer driven, coordinated with NMEA networks to control and helm systems. More costly than standard equipment, can be integrated into commercial navigation systems.
I was taught to not bother with LAN, just shoot a regular LOP around noon and be done with it. With modern calculators it’s actually easier to reduce a normal sun line anyway.
could see that. In the days of tables, LAN was a much much easier calculation. Spent a few months in Antarctica and we got to shoot LAM ( local apparent midnight )
1 Like
Don’t really want to revive this thread to but I’ll put is this way.
If you were put in charge of risk assessment for say 1000 ships, bulkers, tankers, container ships, RO/RO and so forth would your first memo to the fleet be that you wanted everyone to start practicing celestial in case the GPS failed?
If I was down in the trenches on a big RO/RO in shitty weather trying to slog my way though a coast-wise without killing someone I’d think that the person who sent that memo was an idiot.
1 Like
CelNav is the equivalent of throwing a log tied to a knotted line off the stern to measure your speed, (You never know when the Doppler might break!) or lead lines (never know when the Fathometer might break!), or Morse over flashing light (the radio might break!), or sails (the engines might break!), or timber raft building (the ship could sink!).
I enjoy CelNav. I enjoy baffling the kids with stuff they don’t learn in school (lunars, double altitudes, deriving longitude by moonrise without a clock). I also know these skills are oddities of a bygone time that are as likely to help me as an astrolabe.
while I agree in principal - I think it is still important for officers to be able to evaluate what is happening without being overly reliant on electronics. Watching movement of bubbles, ect alongside is still useful to see movement at slow speeds, looking for, and using natural ranges on anchor watch to check for dragging, bearing drift - nut just over the compass - but out the window, and many others. Cel Nav IMO is part of that same mind set that is just part of a healthy skepticism of electronics and an ability to confidently navigate the vessel without them.
As an example, years ago I boarded a vessel, at anchor that my company had on charter and which we believed to be aground, as an observer for our interests. The Captain insisted he was not aground and kept pointing to his electronic chart. My simple question back was, Capt if you are not aground, why are you pointing in a different direction than all the other ships at anchor.
2 Likes
I agree with the general mindset you’re describing here, a kind of total, constant awareness to the situation, the ship, environmental factors and so forth. But I think celnav has limited value here because unlike the bearings of landmarks or weather conditions, things that can be directly observed, reducing sights has too many steps in the process to be usable in that way.
Plugging the daily position into a spreadsheet yields useful information, days run and so forth but it’s not the same as the way a ship feels in a turn.
1 Like
“reducing sights has too many steps in the process”. There is an App for that! DR from that thumbprint on the chart while you fire up your version of a PPU with the BT GPS that reads all navigation satellites not just one system. That fails then it’s time for the sun gun. You may have to change Apps.
2 Likes
I’ve come across a couple of items about this which deserve a new thread but here is one from a professional writer, Tristen Gooley that exactly nails what I’ve been trying to get across, also the point @texastanker makes in his post:
The Future of Celestial Navigation
The saddest thing for celestial navigation is the way it is taught these days – if it is taught at all. I learnt through the RYA Ocean Yachtmaster course. It is effective in many ways, but the celestial navigation part (by far the lion’s share of a 5 day course) did not improve my understanding of the natural world one iota. It is such a great pity that the subject is so often presented as being about Greenwich Hour Angles and error corrections. When I teach natural navigation it is about the earth, the moon, the sun and the stars. I will happily concede that someone using conventional celestial navigation can get a more accurate fix than the hands-free navigator. However, their understanding of what is happening around them and its beautiful interconnections and interplay, may not compare.
This is the key difference and celestial navigation’s Achilles heel in the modern navigation environment. It is a technical business that uses an instrument and requires practiced skills, but for all that it does not rival more modern instruments for accuracy. I would encourage those who treasure celestial navigation and enjoy practicing it, as I do from time to time, to consider changing the way it is taught, portrayed and defended. I am convinced that its future would be more secure if its proponents surrendered some of the high ground of claiming its necessity and instead championed its role in improving understanding and awareness
5 Likes
My brain really likes understanding WHY as opposed to just learning the procedures for how to get an answer. The problem is that celestial is a complicated topic and takes an entire semester at an academy just to teach the lowest common denominator the basic procedure how to get a fix. I had the opportunity to take an elective course, Celestial Navigation II, which was basically all the theory behind it and loved it, but some people really struggle with that kind of stuff.
It’s a bit like my experience with the the magnetic compass. After three months tangling with Weber metres and formulas I can barely remember existing, including formulas for susceptibility, we were finally granted a look at a magnetic compass. Unfortunately the magnetic compass was mounted on a deviascope. An instrument of torture where the candidate, us, played around with tiny magnets under the gaze of the examiner, and tried to explain our reasons for each action we took.
Practical swinging of a ships compass at the end of the course was by contrast, enjoyable.
1 Like
I don’t expect there will be any changes in the way celnav is taught. Taking a more organic approach rather then just teach a step-by-step process is likely not cost effective.
The point I was thinking about was that in most cases the teaching process is too abstract to increase the mariners understanding.
For example, the situation of a ship passing a nearby point with a light. If the mariner recognize the ship is too close (or too far) from the point just by observation, a very concrete process is being used. Very much similar to the way we navigate through a house.
If an aid is used, say a quick check of the range on radar or using the EBL for bearing change, that’s still basically the same method. Same with using parallel indexing
On the other hand once the change is made from using bearing and ranges as an aid, to the full method of plotting bearing and ranges on a paper chart with a track-line, DRs and so forth than the tools are no longer being used as a aid. Instead of increasing situational awareness time taken plotting decreases it.
Something close to a virtual reality has been created on paper which can be used as a substitute for true situational awareness.
Celnav is worse in this regards because diving into the HO229 with the triple interpolation and so forth is even further removed from directly observed reality.
This by the way was the augment made against the anemometer here and elsewhere. That observing the effects of the wind on the sea was an aid to situational awareness but that using an instrument as an aid (much like taking a quick radar range) was somehow going to decrease SA.
Agree - think the core points is something that used to beat into us. That you should know your position by all available means, and have a healthy skepticism of relying on one to too much of a degree. Secondly to chose the appropriate method according to the situation. It is not appropriate to take stars in pilotage waters, etc etc.
Secondly - her " natural navigation and all the methods you mentioned - especially relating the radar picture to your position, a good and updated DR plot, understanding bow and beam bearings, in other words all those things that can give you a good idea of your position without plotting it do 2 main things. They can keep you in the window, with confidence, when traffic demands it. And it is your “this does not make sense check” when your electronics lie to you .
Last point - i don’t think cel nav is esoteric, or a just for one skill. It is a time proven method of finding ones position, and in the instances where you lose electronics for any number of possible failures it can be used. And it is a skill, esp taking the sights, that needs to be practiced to be useful.
It is a tool for the tool box, and although probably little needed these days, if there comes a situation when it is needed - it is too late then to become proficient at it.
As one whom the start of my seagoing career predated the 1974 Solas convention for the requirement of radar on ships of more than 1600 tonnes my views on good navigation practice are different from somebody who started their career at sea with GPS and ECDIS.
As new equipment was introduced, and tankers operated by oil majors got it first, we studied the manuals and self-taught ourselves to use it.
ARPA and the IBM system 7 computer, a forerunner of ECDIS using TRANSIT SATNAV and Decca being examples.
I am firmly behind the new approach in requiring formal instruction in the use of new navigational equipment and realise that some of the skills that we used, like sailing in fog without radar, is a bit like requiring someone to learn how to harness a horse before they can get a drivers license.
1 Like