RYA Yachtmaster Ocean

Become a Yachtmaster Ocean

Celestial Navigation and more

For centuries, the Sextant has been the ultimate status symbol of a seafarer. The mariner who could handle this precision instrument and master the necessary calculations in order to find his position by means of the stars, the sun, the moon and the planets, ruled the seven seas.

Although GPS has turned this once essential skill for ocean sailing into a backup system, it is still important to master. What if… you are struck by a lightning? No matter how many GPS’s and iPhone’s you have onboard, the risk is there will not remain a single working piece of electronics. And what if… you are in mid ocean with hundreds of miles to safe haven at that point in time? Will the compass still be correct, by the way? There have, in fact, been recorded instances of a lightning strike changing the polarity of the compass so the needle points south instead of north.

It should further not be forgotten that, while the entire GPS system is owned by United States government, it is, in fact, operated by the US Departure of Defence. While the US claim that it has never been switched off so far, even in areas of conflict, its reliability is not even guaranteed by the US: On the Official U.S. Government information site about GPS they write:

“Like all radio-based services, GPS is subject to interference from both natural and human-made sources. A civilian GPS unit can lose reception in the presence of a device designed for intentional radio jamming. This can also occur during a solar flare. For this reason, the U.S. government strongly encourages all GPS users to maintain backup capabilities for positioning, navigation, and timing.”

But even without the above overhanging threats, it is an indescribable beauty to monitor your own little boat traveling on our blue planet earth with all the stars around. Celestial navigation puts you in context with the universe and the stars above become guides and meaningful friends. The earth turning around itself and then again around the sun and the moon around the earth…. it all becomes so beautiful and obvious!

I do believe in celestial navigation and have enjoyed it for a decade having used it as a second mean of navigation besides GPS. But it is not until lately that I have become a qualified RYA Yachtmaster Ocean Instructor where I am officially able to teach it as well. You are welcome to join!

When doing my Yachtmaster Ocean courses, my aim is to take celestial navigation down to earth, so to speak. There is so much hush-hush and mystery around the subject and it almost seems as if the “masters” try to keep the secrets for themselves, presenting it in an unnecessarily complicated way. This is a shame, since, in all honesty, it is not difficult at all and easily understandable.

In a nutshell, what you do is to measure the angle between the horizon and the sun using a sextant. Then, you compare your measured angle (called “Ho” after a couple of corrections) to what you should have measured (called “Hc”, which is found in tables), had you really been where you think you are. If you measure the same angle as stated in the tables you are obviously exactly at your assumed position. In most cases, however, you measure a slightly different angle, due to the fact that you are a bit off from your assumed position. If you know the direction of the celestial object (called the “Azimuth”) and how much your own measured angle (Ho) differs from the angle you should have measured (Hc), the task is easy: If your measured angle is smaller than the one from the tables, you are further away from the celestial object (e.g. the sun), if your angle is greater, you are towards. That’s the entire secret! The rest is using tables in order to look up the angle you should have measured (Hc) and the direction to the celestial object (Azimuth) as well as do some corrections to your own measured angle (in order to get Ho). That’s it!

Unfortunately, many students get so involved in tables, templates and corrections that they loose track of the above overall concept and get lost on their way. They just can’t see the ocean because of all the waves (which is the marine equivalent for not seeing the forest because of all the trees).

When you know how far you are off your assumed position you draw a line in your chart called the “position line”. You are along this line somewhere. Since you want a fix and not a line, you need two of those lines: Where they cross, that’s where you are. So, either you take several shots at the same time (sun, moon, stars, planets) or you have to wait for the sun to move on, in order to make a second “shot” a couple of hours later.

In my view, the topic of celestial navigation should comply to the following requirements:

1. On an ocean passage, one should be able to use a sextant as a second mean of navigation, i.e. as a backup
2. The subject should be kept simple and explained in an easy to understand way
3. A method should be presented which students can remember even if you don’t use celestial navigation for some time (use of a sketch rather than a template)
4. No calculator should be allowed, since the entire idea is to navigate after a lightning strike, where all electronics might have gone
5. Although the entire RYA syllabus is to be taught, it should be explained to the student that some corrections from the tables could be summarized, bundled or estimated in order to keep it simple.
6. When students understand which arithmetic calculations could be kept to a minimum, mistakes can be avoided

Obviously, there is more to ocean sailing than celestial navigation. Unfortunately,  on many RYA Ocean courses a lot of time is spent on explaining celestial navigation, leaving little room for anything else. Ocean weather and ocean passage planning is possibly covered in a few hours only and important topics are left out completely, despite being very important for ocean sailing.

In my courses I try to at least touch and discuss all of the following topics:

1. Celestial navigation, emphasizing on shooting the sun and doing a compass check.
2. Shooting stars, the moon and the planets are covered in a more general way. Basically, it’s the same thing with the only difference that some more corrections and hence arithmetic calculations are needed. The selected stars are actually easier, their only drawback being that you can shoot them at twilight only.
2. Ocean passage planning (useful sources, routing charts, prevailing winds, ocean currents etc)
3. Global ocean weather pattern and weather sources (GRIB, routing companies, routing software, Weatherfax, InmC, Navtex, HAM, etc)
4. Storm tactics (escape from hurricanes and weathering storms)
5. Living onboard while on passage (watches, provisioning and storage of food for ocean passages, pests, water management, maintenance, rest, social and psychological aspects)
6. Ocean communications (all types of Satcoms, SSB, e-mailing from offshore)
7. Seasickness, security, risks of accidents and other medical issues
8. Power management (batteries, generators, alternators, solar panels, wind generators, emergency power etc)
9. Customs and other issues when entering a foreign country

The above syllabus can unfortunately not all be covered on a normal RYA Ocean course spanning over no more than 5 days. If you are interested to cover them more in detail and trying them out in real life, you are welcome to join on one of the offshore or ocean sail training legs of Regina Laska. Don’t hesitate to contact us.

If you are interested to take the RYA Yachtmaster Ocean certificate of competence you need some pre-examination experience in order to apply. Please note that the qualifying passage mentioned below may be gained on one of Regina Laska’s ocean sailing legs.

1. You must be the holder of a Yachtmaster Offshore certificate of competence in order to be examined as an RYA Ocean Yachtmaster (please see here how to get it)

2.  A qualifying passage as skipper or mate of watch of at least 600 nm in length according to the following:

The candidate was fully involved in the planning of the passage, including selection of the route, the navigational plan, checking the material condition of the yacht and her equipment, storing spare gear, water and victuals and organising the watch-keeping routine; During the passage a minimum non-stop distance of 600 miles must have been run by the log, the yacht must have been at sea continuously for at least 96 hours and the yacht must have been more than 50 miles from land while sailing a distance of at least 200 miles. Please see the ‘definition of passage’. All qualifying seatime must be within 10 years prior to the exam.

3. During your exam, you will be asked to present a narrative account of the planning and execution of your qualifying passage mentioned under 2.

4. During your exam you will be asked to present at least one sun-run-sun sight to the examiner. You need to be able to explain your sights, the reductions and plotting. Don’t worry, this will all be dealt with in the Ocean course. The celestial navigation does not necessarily have to take place on the qualifying passage either and may be part of your RYA Ocean course with one practical day at sea.

If you wish to prepare yourself for ocean cruising, not only in order to take the RYA Yachtmaster Ocean certificate, I cannot recommend Tom Cunliffe’s new book “The Complete Ocean Skipper” warmly enough. This highly comprehensive book spans over all aspects of ocean cruising surpassing the RYA Yachtmaster Ocean sillabubs. Tom has the fantastic gift to tell a story rather than lecturing when he writes about his deep experiences and knowledge. If you wish to receive a signed copy, please buy it directly from Tom here.

For further details on the RYA Ocean courses and how we can help to obtain an RYA Ocean Certificate of Competence, please contact me.