Pesky Rigel Kent

Where Next?
Bob Williams
Wed 12 May 2021 03:29
Noon Position: 33 05.0 S 160 25.5 E
Course NW Speed 6 knots
Wind: NE, F4 Sea: moderate Swell: NE, 2 meters
Weather: cloudy, mild
Day’s Run: 66 nm

The day’s run for the last 24 hours is the first one of less than 100nm this passage. A little disappointing but not surprising considering we spent much of the night becalmed and drifting. We motored for a few hours in the late afternoon and again for an hour from 2300 to midnight. We managed to find a little bit of breeze in the evening and the seas had settled sufficiently so that the sails would not just slat against the rigging and chafe themselves to pieces.

I also managed to get a set of star sights just after sunset, the first this passage. I took a total of eight sights, two each of four stars. The idea is to pick four stars about 90 degrees apart, so two end up opposite each other. Then, ideally, in accordance with some error theory, one takes four sights of each star. The stars being at right angles to means that the position lines derived from them also cross at right angles, making for a more precise fix. And the idea of choosing stars opposite one another helps to compensate for any unknown errors, such as an incorrect index error.

I am pleased to say the sight reduced down to pretty tight fix, Initially I worked them all out long hand, using the almanac and HO208 tables. However, one star, Rigel Kent refused to cooperate. I checked over my calculations several times but could not work out what I had done wrong. I suspected I might have misidentified the star but when I reduced it down using some navigation software, it tied in beautifully, so that clearly was not the problem. I pored over my figures until midnight and then had to admit defeat. Maybe I could work it out on the morrow after a bit of sleep.

I shut down the engine (I had already handed all sail) and retired to my bunk allowing Sylph to drift until some wind picked up. I stuck my head up every so often during the night but the Australian flag on Sylph’s backstay either lay limp or waved feebly from side to side as Sylph rolled to the NE swell that has been ever present since our departure from New Zealand.

At 0600, with the rosy fingers of dawn just starting to peer over the eastern horizon, I found the flag fluttering quietly but standing out straight to the gentle breeze. The breeze was light but I figured strong enough to keep the sails full and prevent them from slatting excessively. The breeze was from the ESE so I got all sail up and poled the jib to starboard, allowing Sylph to run before it to the NW.

As morning wore on, the breeze has freshened and backed into the NE. Consequently we have dropped the pole and are now beam reaching across the breeze at a brisk six and a half knots.

Looking at the weather faxes from the Australian Met. Bureau, it seems that some potentially unpleasant weather is heading this way, with a trough coming down from Queensland and a front heading up from Tasmania, joining forces midway across the Tasman Sea late Thursday, early Friday. I don’t think conditions will be too bad but am making ground to the north to see if I can avoid the worst of it and, hopefully, maintain a relatively favourable slant of wind for as long as possible. I suspect by late Friday we will be punching into a fresh W’ly headwind.

But, in the meantime, we have fair breeze and are making good time. If this breeze holds for another 24 hours, we might get to sail past Lord Howe Island.

Now I really must get back to Rigel Kent and work out what I did wrong in my calculations.

(It occurred to me yesterday that some 42 years ago, as a green Midshipman, I was heading in the opposite direction on board the RAN’s training ship, HMAS JERVIS BAY, putting my theoretical celestial navigation training into practice. While, even after all this time, I am still struggling with crunching numbers, I do think my ability to reduce a set of sights to something approximating a useful fix has improved a little bit. Though, it has to be confessed, while being able to navigate by the stars was an important skill back then, now it is little more than an obsolete anachronism – a bit like me.)

All is well.