2017 Atlantic Crossing, Celestial Navigation across the pond

Day 21. Venus and Jupiter change places, the icing is on the cake

Today started at 0530, I plotted a quick EP to work out my LHA and GHA of Aries (me on the ocean compared to the Sheep on the dish) so I can go on deck and take a dawn star sight.  
I get sights on Arcturus, Spica, Sirius, Betelgeuse, Capella and I just miss Deneb before she vanished into the daylight (partly due to dropping a cup of tea all over the deck, I had to race for the kitchen roll before the boat rolled back to starboard sending tea down the steps and onto the deck below – I was too late!). 

It is too cloudy to see Polaris in the north, but I do see three satellites racing by. They sure shine bright in the early morning light, each one looked almost as big and bright as the ISS.  There was also an enormous falling star (possibly the 3rd biggest I’ve ever seen). 

In the east it is clear are two planets rising in the hazy of the breaking dawn.  The first one up I assume is Venus and the second Jupiter.  I take sights on them both since they are there, although the second one is probably too low in the sky to be useful.  

I have the 0600 to 0900 watch this morning, which is fabulous.  There is not a breath of wind out here this morning and the ocean smells kind of fishy or “ozone” as Dad calls it, that low tide smell at the breakwater, superb!  The sea is like glass, it is a beautiful morning and everyone else is in bed, so there is only me sat here to enjoy it.  Lovely! Thank goodness again for the catamaran and her large fuel tanks.  Luckily the forecast is suggesting 25 knots of breeze for us for the next few days, so hopefully we can sail the rest, if we can get this hotel up to 7 knots we’ll be there in 2 or 3 days….


As the sun rises I’m sat on the top deck doing my calculations on the sights I’ve just taken.  It turns out that this is the most accurate and beautiful star sight I have taken yet, all the lines cross almost at the same point, giving me a fix that I am totally confident of our position to within 5 miles (the thickness of the pencil cross on the ocean chart).  I love this, star navigation is my new favourite thing.


For good measure I elect to add the sight reduction from what I had assumed to be Venus, so I go through the calculations and get an answer that doesn’t make sense.  I know my LHA is correct, the star fix has proved that already, I check the GHA for Venus and declination – also correct.  After a few minutes of musing I put the same figures in but this time I use Jupiter instead of Venus and sure enough, the numbers add up.  In the week I have been off watch for dawn Jupiter and Venus have changed places in the sky.  This really is the icing on the cake for this morning’s fix, I really am starting to understand all this.


Shortly after 0900 a swallow lands on the rail on the port side.  The little guy was ready for a little rest, he must have been flying for some distance to be out here! He stayed with us for almost an hour, it was great watching him having a little clean of his feathers and keep his balance perched on a wire on this rocking boat.  I wanted to make a little bird bath for him, but figured I’d probably scare him off in the process.  Then he was gone, he is definitely winning the race to the Caribbean!

With not a zephyr of wind anywhere it sure was hot out on deck.  I’d not long retreated to the cool of my cabin when I heard loud voices, unusually loud.  I couldn’t work out what was going on, had they spotted or whale? It all sounded rather exciting, I headed for the deck.  The engine was off, the boat moving at less than half a knot.  The sounds I heard were coming from a couple of the crew swimming under the boat between the hulls.  It was the perfect day for it!


The sea is SOOOOOO blue today and very very very deep (5000m according to the chart).  400 miles away from land, here I am enjoying a cooling swim around the boat, certainly not your average November day!  Pleasant as it was I quickly began to feel like shark bait and was soon back on the boat. 

Out of the sea and straight into a hot shower – ha! This is living 🙂



The cool of my cabin was the best spot this afternoon.  I definitely have the best cabin, it is almost sound proof, there are no pumps or pipes running through it and being at the bow I get the breeze through three hatches, so it is the coolest place on the boat. 

 I force myself to wake up when I realise I am dreaming about Henry’s whisky!  Damn that bottle of Oban.  Just a wee dram would be such a treat, but I know one wee dram would rapidly lead to another….. And another…. And most likely another.

So I get up and set about working out my EP for this evening’s stars. Twilight and dinner seem to coincide exactly – again, so under pressure I shoot Vega, Fomalhaut, Deneb, and what I believe to be Nunki, but the numbers don’t add up, so I suspect I’ve got this one wrong.  Shooting stars in the evening is much trickier at least at dawn there is time to identify each star from its constellation before the dawn horizon comes in to view, as dusk I am still guessing somewhat.  Vega, Deneb and Fomalhaut I seem to have found, but the others are still a guess, so I don’t hold out much hope for a pretty fix like this morning’s one.  The Moon is also present in the western sky, just showing a sliver of a Cheshire cat smile, I take a sight on the Moon too for good measure, since I am only confident on three of my stars, a position line from the Moon might tidy things up a bit for me.

Now it is 2100, I have one more hour on watch, then up again at 0200 to 0600 and the chance to shoot the dawn twilight stars again. It is so still that Vega is actually putting a reflection on the sea.  

I’ve just seen lightning on our northern horizon, but since there isn’t a breath of wind it should stay away.  I don’t like thunder and lightning and I’m pretty confident that we are the tallest thing here for many many miles…..



2 comments on “Day 21. Venus and Jupiter change places, the icing is on the cake

  1. Hi Carrey,
    Thank you for your delightful narrative about taking star sights on your Atlantic crossing. It took me back to my young days at sea in the early 70s when astro was the only reliable way to navigate once land had dropped over the horizon. It is lovely to read about your pleasure in taking sights using stars, planets and the moon (I am sure that you are a dab hand with sun fixes as well). Well done! There are plenty of professional navigators who aren’t as proficient as you are.

    I remember the pleasure of becoming familiar with a pattern of stars during the first couple of days of a voyage. They felt like old friends by the end of the voyage. In fact, I still regard some of my old favourites with great affection when I look up at a clear night sky at home.

    I was interested to read your comment on Polaris. I used to enjoy taking a fix on Polaris (if I could see it at twilight). Occasionally I managed to snatch a fix on Polaris in the depths of night when the moon was bright enough to give a horizon in the north. Using the Polaris table in the Nautical Almanac to quickly get our latitude was particularly pleasing!

    I am planning to do some ocean sailing with my granddaughters over the next few years. I hope that I will be able to introduce them to the pleasure and satisfaction of celestial navigation.

    Keep up the good work!

    Kind regards, Chris


Leave a Reply