Map Display

Sunday, 26 February 2017

A rough shiny day!

This has been a tough passage ... we haven't been able to relax much because all along our path it seems we've had 3 to 5 meter waves ... and we've diverted from our course to avoid the even worse 9 meter waves. There have been many sail changes and a lot of uncertainty.

BUT today we sat out in the beautiful sunshine looking at the cobalt-blue shiny waves.

We're now using the same 2007 chart we used for our last NZ-Chile nonstop.
2007: we were at 43 degrees South
2017: we're at 37 degrees South
2007: water temperature: 13 degrees C
2017: up to 20 C
2007: 33-day passage
2017 (probable): 39 days
2007: we were "knocked down" (boat slewed sideways and top of mast hit the water)
2017: a more conservative navigation schema will preclude a knock-down

Earlier, we got a chance to have calimari for dinner when this gift arrived from Neptune!

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At 2017-02-27 06:04 (utc) our position was 37°07.29'S 115°36.18'W

Saturday, 25 February 2017

BART

When tropical weather disturbances get a name (BART) rather than a cryptic number (such as 13F), you know they are getting serious. Having come to life in French Polynesia nearly a week ago, BART spun up into a typical hurricane (perhaps near-hurricane), left the tropics and headed our way. The New Zealand weather forecasters who concern themselves with this bit of ocean go beyond a "gale" warning to the more serious "storm" warning in their caution to stay away from its still-kicking remnant.

Our other forecast tools suggest winds over 50 knots and describe seas over 8 meters in height; definitely not something to be trifled with.

So here we are still going north ... When the center of the storm passes to the south of us tomorrow evening, we expect winds of less than 30 knots where we will be: all because of the few hundred miles of evasion-distance we have been accumulating during our recent off-course days.

Of course, then we'll have to scurry back again to the forty-something south latitudes we need to provide a reliable source of west winds to speed (??) us on our way to South America.

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At 2017-02-25 18:53 (utc) our position was 38°06.94'S 120°10.87'W

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!

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

Sunday, 12 February 2017

Two steps forward, one step back

The gale sweeping down from the north towards us decided to intensify. We in turn decided to try to avoid the worst of it by heading for the nearest exit ... in this case, around the back (western) side of the low.

This is being penned to explain the little jog in our path. Even on the gentler path we took, it was all accompanied by lots of rain, big (5 meter) waves and howling wind.

Now we are again romping (perhaps "loitering" better describes our pace) towards the east with a fair wind. A wind that is likely to be with us as far into the future as the forecasts go.

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At 2/13/2017 04:04 (utc) our position was 48°25.29'S 156°24.59'W

Thursday, 9 February 2017

How far south?

Until the early part of the nineteenth century, sailing ship routes were based not on any scientific foundation but simply on what had worked in the past.

Mathew Fontaine Maury, a lieutenant in the United States Navy at that time prevailed on a large number of military and merchant mariners to pass to him logs of their weather readings during their various voyages. From this, Maury compiled charts showing the likelihood of winds of various directions and strengths in different parts of each ocean.

These charts, updated with modern observations, are available today to assist in the planning of ocean voyages. While day-to-day routing is based on actual weather and short term forecasts, the grand plan of the voyage is based on "Pilot Charts" descended from Maury's original work. From these maps we can tell, for instance, that winds in May in French Polynesia are calm less than 1% of the time and blow from the west almost never - a great region and time in which to make your way west! Similarly, in February in the area in which we now sail, the winds are said to virtually NEVER blow from the east. As sailboats cannot easily make ground directly toward the wind, we would seem to be well positioned for an eastbound passage.

Unfortunately, "virtually never" is not the same as "never"! Low pressure weather systems usually travel around the bottom of the world to the south of the roaring forties reinforcing the west winds prevailing in this region. Nonetheless, in the warm sub tropic waters far to the north of us a complex low has chosen to develop. It now plans to move to the southeast across our path and produce gale force easterlies exactly where we would like to be in a few days. As such winds are something we would prefer to avoid, we keep deviating south. On this path, the gale force east winds should lie to our north until the weather system passes to the east and dissipates. We expect to return to somewhat more clement latitudes in a few days after friendlier winds reestablish themselves there.

Of course there are limits to this! Not much to the south of latitude 50, Antarctic icebergs start to be a concern. As the weather situation develops, rather than be forced even further south, we may need a different plan ... perhaps we will simply heave to and wait while the contrary winds howl themselves out to our east.

A negative aspect to our southerly route is the change in cabin temperature from merely "uncomfortable" to "depressingly cool". Yes, we have a very efficient heater aboard but we would prefer to save our diesel fuel for emergencies as our route will take us over 1000 miles from land for a few weeks into the future. As we approach South America in March, we may choose to warm up the boat ... or we may be so inured to the cold by then that we can't be bothered. Notwithstanding this comment about the chill, it is actually the same temperature here at 48 south as it was 250 miles further north on our crossing ten years ago. Could it be that the warmer temperatures this year are leading to the formation of the tropical lows and to the displacement of the wind patterns further south than usual?

As the weather system that has favored us with a fast passage over the past week draws to a close, we have slowed from seven to five knots. From this remote place, far away almost straight north are the islands of, first, Rarotonga and much further again, Kauai. Traveling due east over three thousand miles you find Chile; but perhaps surprisingly, west along this latitude, you find no land at all until the coast of Argentina. Our nearest land, New Zealand's Chatham Islands, is 650 miles behind us and we have sailed almost 1200 miles since leaving Picton just over a week ago.

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At 2/9/2017 21:48 (utc) our position was 47°51.25'S 159°57.18'W

Friday, 3 February 2017

At sea

After a thoroughly enjoyable seven months in Australia and New Zealand, we have now set out on the long road across the far south Pacific to Chile.

The first 0.4% of our voyage was certainly a gentle introduction! Anyone who has traveled the ferry route between New Zealand's South and North Islands will be familiar with the hill-enclosed passage along the quiet waterways of Queen Charlotte Sound and Tory Channel. While a gentle rain did dampen the view, there were no waves or wind to speak of and the only motion was a subtle swirling from the tidal currents in Tory.

Then, as if to remind us that this was to be an OCEAN crossing, our first night out featured winds up to 40 knots (70 kilometers per hour). We kept reducing sail to control forces on the rig until there was very little left at all - and still we kept galloping along. By morning, the front had passed and all was gentle sailing in the sunshine. That will certainly not be the last gale we experience on this crossing!

* * *

A digression for trivia buffs: When we speak of "miles" in these blog postings, we always mean "nautical miles". Until recently, marine navigation (and until the 1970's, long distance air navigation) used a branch of mathematics called spherical trigonometry to calculate position using the sun, planets and stars. The answers came out as angles measured along the earth's surface rather than as distances. It was thus convenient to use an angular measure for distance. The nautical mile was born ... equal to one minute of arc or one sixtieth of a degree measured on the earth's surface. Thus one degree of latitude spans 60 nautical miles. In a comparison to units commonly used on land, one nautical mile is 6080 feet (15% longer than an American/British mile) or just under 2 kilometers.

Speed in ships (and planes) is measured in knots (not nauts and not knots per hour!) equal to one nautical mile per hour. 150 years ago, speed would be measured with the help of a long reel of rope terminated in an edge-weighted floating block of wood that would grip the water. Along the rope at calibrated distances were a series of knots. The block was thrown in the water and, as the rope unreeled into the ship's wake, a sailor noted when the first knot ran through his hand. He turned a sandglass to start timing and counted knots as they ran off the reel. The number of knots in the rope that passed through his hand before the sandglass ran out was the measure of the ship's speed.

Today, with knot reels now many years in the past, container ships make 22 knots through the water while airliners high overhead cross oceans at a speed of 480 knots!

* * *

As I write this, Picton, our point of departure, is 220 miles to our northwest as we make our way at 7 knots towards Valdivia, Chile some 4700 miles ahead. Eastbound sailing voyages across the South Pacific are made in the forties of south latitude to take advantage of the west winds prevailing there. This ocean area has long been known as the "roaring forties" because the winds blow with considerable strength - more than we really need or would like in a small vessel. But it DOES move a boat along.

The routes here were the last bastion of sailing cargo ships as they could still compete economically with the steamship when it arrived on the scene. 3000 ton square-riggers carried grain from Australia to Europe right up until the start of World War II - long after steamships had taken over all trade in the northern hemisphere.

From day to day, our route is re-planned to take advantage of the ever-shifting weather patterns and to avoid any particularly violent storms by shifting to the north or south or by slowing down to allow a weather system to advance ahead of us.

In a couple of days we will pass near the Chatham Islands, a New Zealand outpost marking the 10 percentile of our trip. That will be our last milepost - a quick glance at a map shows no islands at all across the rest of the ocean. Our distance from land will gradually increase to just over 1000 and then will stay at that figure for most of the crossing. Our feeling of progress will come from resetting the clocks an hour every four or five days and from noting which of a succession of inhabited islands or cities lies far far to the north of us.

We have many miles to go!

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At 2/3/2017 12:13 (utc) our position was 42°58.32'S 178°21.22'E