Map Display

Tuesday, 21 February 2017

Halfway!

With the gray skies above and the few birds foraging and soaring over the endless four-meter waves, our halfway day seems much like the days preceding it. Nonetheless, in a world of few treats, it is special to us.

We have presents to open and some candy packages to demolish. There is also that grand new feeling that we are moving closer to Chile rather than further from New Zealand.

Our furthest point from land on this crossing was actually a few days ago when we reached 1250 miles from both New Zealand's Chatham Islands and French Polynesia's Rapa Iti. We now find ourselves a "mere" 1100 miles south of Pitcairn Island of "Mutiny on the Bounty" fame. That's still a daunting distance - seven days travel for us. If you wanted a photo of our tiny white speck in this vast wilderness, a jet from Easter Island, the nearest airport 1380 miles away, could visit us in a six hour round trip. It is as if you were the only inhabitants of Toronto and the nearest people - but only a few dozen - lived in Miami ... with no-one any closer in all the space between!

This is not a commercial shipping route. Our empty world has featured no ships and no airplane contrails since we left the coast of New Zealand almost three weeks ago.

Five days ago as we were easting along the forty-ninth parallel of south latitude, it seemed that we would eventually pass "Point Nemo", the furthest you can get from land in the whole world. That would have placed us equally 1465 miles distant from Pitcairn, from Easter Island and from Cape Dart, Antarctica. That will not now happen as we have wandered away to the north.

So how does all this work?

Every day, in the late afternoon and early evening, the ionosphere configures itself so that short wave radio communication is at its best. That is when we exchange our incoming and outgoing emails with a shore radio station (currently Chile) that is itself connected to the internet. One of our outbound emails is a request for weather maps and text forecasts and attracts an automatic email reply with the requested information.

We look at text forecasts for the western South Pacific from New Zealand, the eastern part analyzed by Chile and tropical storm forecasts (they move in this direction before dying away) from Fiji. These are made much more understandable by an accompanying map of wind, wave and atmospheric pressure of much of the Pacific. Another map of detailed winds in our area for the next few days of sailing completes the picture.

Using priorities of 1) avoid really nasty weather even at the expense of reversing the course for a few days if necessary, 2) less importantly, avoid calms and headwinds and 3) least importantly, try to find a measure of comfort (hah!). The maps, texts and these priorities are all distilled down to the route to be followed and heading to be steered based on predictions out five days or so into the future. Any forecasts beyond five days are a bit fictional and, anyway, it all changes enough the next day that the whole process is repeated and the heading revised as necessary.

We try to infer from the forecasts what sail configuration will be optimal for the coming night. This is in order not to disturb the four-hour stretches of sleep the off-watch person gets with sail changes that could easily have been predicted and made before dark. There seems to be enough clambering around on deck in the black of night, though, to suggest that this doesn't always work, but we do try.

Looking back at our path so far, the jog way to the south was to avoid east winds blowing in the forty to forty-five degree latitude range in our first two weeks. The race toward the northeast now deals with a series of deep low pressure cells bringing gale force winds to the latitudes in which we had been sailing. Better weather expected to the north appeals to us more than the reduced distance obtained at higher latitudes. A tiny benefit to being further north is that the rising sea temperature is leading to the cabin temperature actually becoming tolerable.

An added puzzle this year - or is it this month - is the instability in the tropics leading to near-hurricanes (failed hurricanes?) spinning down across our path from the north. These too must be watched for and avoided.

And "only" 2500 miles more of this await us!

-----
At 2017-02-21 16:15 (utc) our position was 43°33.54'S 130°00.00'W

1 comment:

  1. This Is Capt Pedro (Peter) running a charter in NZ BOI. Sweet life down here. Back to Vic in two weeks. Love your reports. Be safe. P

    ReplyDelete