Day 81 - Below Horn and Rounding Plan

Over coffee at 6.30 AM I saw that we were at latitude 56S00.07, placing us farther south than the Horn.
The latest spot reports (i.e. wind and other prediction data on any lat and long of my choosing, covering the next 4 days) predicted no gale winds for the next 4 days, through 19 January - the only wind speed over 30 knots was a 6-hour period of 33 knots on the 17th. This was very, very good news because it should see me through the final dash past the Horn.
If I could have counted on N-NW winds for long enough I would have changed course immediately and made directly for the Horn across the shallows, but the prevailing winds were to be from the west meaning that I would have to gybe my way past the Horn. I decided to stick to the plan and make for the corner of the shallows south of Diego Ramirez Island more than a degree south of the Horn at lat 57S18. Once I rounded that corner I could easily lay the the east side of Staten Island, which was the same line as the edge of the shallows. But that turn was still 300 miles away. I would actually cross the meridian of the Horn still headed SW just before making that turn. Once I made the turn I would have a straightforward and safe (in navigation terms) leg of approximately 200 miles to the east end of Staten Island. Looking at the distance of the various segments on the laptop system I estimated that taking the "safe" rather than direct route would cost me 80 miles in distance, not a high price to pay in light of the benefits. ... And when I think about it, I would have lost much of that 80 mile advantage in gybing my way past the Horn rather than doing it in one big gybe around the shallows.
With the strong and reliable winds in this area I estimated that I'd reach that turning point early on the 18th of January. At that time I would have formally transited the Horn, though I would not consider it a complete rounding. One definition of rounding is "doubling the Horn" - passing from 55S on one side to 55S on the other side. By the time I got to Staten Island I would have doubled the Horn, but for me it would not really be over until I'd gotten past the Falkland Islands.
So all going well I hope to cross the meridian of the Horn on 18 January and reach the east end of Staten Island for a complete rounding on 20 January.
----
We had a fairly rough night. I got the latest grib file at 9.30 PM which confirmed that the winds were stronger than had been predicted, 30 knots. Knowing that 30 knots can mean surges of over 35 knots, at 10 PM I went out and rolled in a bit more headsail even though in the light I could see that it was coping OK. And there was light. Even though it was the middle of the short night I could see the glow of the sun to the SW. In spite of running with short sail we were making good time, undoubtedly helped by the huge following seas and the current, which should be getting stronger until we cleared Staten Island.
I could tell that the gas cylinder was on its last legs. With the flip of a lever I would be able to swap over to the other cylinder, which was about 1/3 the size of the large one. The large one had carried me through 80 days of the passage so I knew that the smaller one would easily support me past the Falklands. I could not complain about the 80 life span of the cylinder because there had been many many hot coffees, soups, cocoas, rolled oats, bread baking, not to mention the meals. Waiting on the stern rail was the large cylinder that Rick had given to me in La Paz (Thanks Rick!!!). On the first calm and non-crisis day I would swap in that full cylinder which should support me to Cape Town.
At 8 AM I went topside. It was a sunny, partly cloudy day with a definite nip in the air - probably in the low 40's F. The sea was still roiled but the wind had dropped to around 20 knots and was predicted to fall further. I rolled out more headsail. Jeff had done a sterling job of steering the boat and did not even require tightening of the control lines. I looked forward and everything seemed in order. I was anxious to do a fuel transfer as soon as possible to minimize the risk of losing overboard any of the vital diesel fuel.
I did a bit more work on the autopilot/Seatalk problem. Rather than open up the instrument panel above the companionway I isolated the Seatalk connection of both the wind and depth instruments from the rest of the network. There was no change. Specifically, the chart plotter could still not see heading information nor did the autopilot control panel stop displaying the "Seatalk Failure" message. At that point I had to conclude that neither of those instruments was putting noise into the Seatalk network. I wanted to isolate the autopilot by simply turning it off at the control panel, but it cannot be turned off at the panel - it is hardwired to the same breaker as the chart plotter. I'll look at that later. There is a Raymarine junction box with 5 Seatalk cables going into it. One is from the daisy chained wind and depth instruments. One is from the GPS antenna at the stern. One is connected to the autopilot computer. The other two go forward, one of which must go to the chart plotter. The fluxgate compass is connected directly to the autopilot computer. I will open up this junction box to see if I can find anything interesting - but not today. I'll also review the information on the problem that Stephen sent me earlier.
Just before noon I gybed the boat in anticipation of a veering of the wind to the NNW which had already begun. In light of the wind prediction I expected to stay on this tack for at least 24 hours. I was looking to the full range of heading options once the wind settled to NNW. During that time I could head directly for the Horn or more southerly toward the turning point at the corner of the shallows. Either way I expected to get much closer to the continental shelf (i.e. shallows).
At noon our position was 56S15, 075W06, giving us a n-n distance of 104 miles in the direction 119T. We were 270 miles west of the Horn which was on the bearing of 087T.
I checked up on the fuel situation and came up with the estimates of 91 liters of diesel in the main tanks and 83 liters on deck, giving me a total of 174 liters. Much as I'd like to do a fuel transfer the conditions are too rough and I know now that I have enough fuel in the tanks to get me well beyond the Falklands. Assuming I don't lose any fuel overboard I should have plenty to get me to Cape Town. Incidentally, I work on a conservative estimate of 1.5 liters of fuel consumed per hour during the battery charging runs.
As the evening approached we were on a beam reach off a 20 knot wind heading east, toward the Horn. I had been very tempted to raise the mainsail for the many expected hours of NNW winds but then I saw winds of 28 to 31 knots in our future and kept the trysail up.
----------
radio email processed by SailMail
for information see: http://www.sailmail.com