Tag Archives: navigation

The hazards of navigation

Last weekend we decided to go for a drive, to get out of town for a little while. We found a place on the map we figured might be interesting – Coalstoun Lakes, not too far from Gayndah and Biggenden, about 140km away. We’d never been there, and maybe there’d be, you know, a lake. Scenery to look at. Maybe some wildlife.

We had some fun confusing the basically dreadful navigation system on the Merc. To start with it wanted us to go to Childers via Torbanlea, but we headed to Maryborough instead. Undeterred, the girl in the console suggested that we should drive to Maryborough, then take the Bruce Highway to Childers, then go inland from there. If we had intended to go via Childers, we would not have gone to Maryborough first. That would have meant a hairpin bend in Maryborough to almost retrace where we’d come from. But I have to say, she’s a persistent little critter. In Maryborough itself she tried to persuade us to go around the block for ages. Even when we headed inland, crossing over the Bruce Highway onto the Biggenden Road, she tried to divert us back to the Bruce. To give her fair due, though, going via Childers would have been shorter. But who wants to drive on the Bruce if you don’t have to?

She gave up eventually, and worked out what we intended to do. She probably sulked.

Anyway, back to Coalstoun Lakes. It’s supposed to be a town just past Biggenden. Judging by the name (as you do) we were kind of expecting a Lake. Maybe two. Or at least a dry area where a lake used to be. But no. No lake on the Merc’s nav, no lake on Maps.Me on Pete’s tablet, no lake on the paper map (admittedly not detailed), no lake on Google maps (see above) – and (surprise!) no lake.

UPDATE: There are lakes! Two, in fact. Volcanic crater lakes. Well, golly gosh. Maybe we should have asked Google BEFORE we went out. Coalstoun Lakes NP.

Spectacular sunset

We pootled around a bit, drove through Biggenden which was NOT jumping on a Sunday afternoon, tried a couple of side roads that led to farm gates, shrugged our shoulders and headed for home. It is pretty country, though, with a range of hills that kind of rear up from the plains. I took a couple of pictures (see above). We’d had a spectacular sunset the previous evening, harbinger of the cloud bands in the photo, part of a front that brought the area (and us, as it happens) welcome rain.

On the way back I noticed a side road on the nav system that would cut off quite a long triangle of road – about 20 km, in fact. We could bypass Goomeri to get to Kilkivan. It was marked on the map as a minor made road, so we decided to give it a try. And this is where the essential not quite accurate nature of both our navigation systems let me down. (I’m the navigator, you see). We came across a left turn from the highway, and judging by the position of the little blue icon that represented our car, I decided this was it. We chucked a u-ey (having already driven past the turn-off) and went down the narrow bitumen road. Our first choice of a fork ended up at a farm gate. The second choice took us into rugged country. The bitumen petered out and the track started to snake around, and cross numerous gullies. Eventually we gave up and resigned ourselves to the main road, including that triangle via Goomeri that we were trying to avoid.

Back on the blacktop we drove another couple of kilometres – and lo – there was a sign which read Kilkivan 27 km! And so we went that way. We arrived home in Hervey Bay just before the rain.

I have been sacked from navigation until I have completed the re-training course.

 

 

 

Blame it on the longitude

1628 map (National Library of Australia)

It’s an interesting fact that of the four Dutch sailing ships known to have been wrecked off the coast of Western Australia, two of them – the Batavia and the Zeewijk – struck the reefs of the Abrolhos Islands and there has long been speculation that a third ship, the Aagtekerk , lies in the deep water off North Island. The question is why? Why didn’t the Dutch navigators avoid these islands?

The basic answer is longitude. In the seventeenth and eighteenth centuries there was no reliable way of calculating longitude because there was no sufficiently accurate means of calculating either time or distance travelled. Sailors used what means they had plus a lot of educated guess work to estimate where they were in the world. Latitude was not an issue; they had the means to find that value with precision but longitude could be off by many, many degrees and many miles.

On their journey from Amsterdam to Batavia, capital of what we now call Indonesia, the Dutch mariners sailed their ships south from the Cape of Good Hope and used the winds of the Roaring Forties to speed them on their way. When they estimated they were far enough east, they turned north, heading for the Sunda Strait and the gateway to Batavia. Remember, at that time they had very little knowledge of the coast of Australia. They knew something lay out there and had glimpses of its hostile shores but that was all. These seas were uncharted. Houtman had encountered the Abrolhos in 1619 – fortunately for him, in daylight – but even if the islands’ existence had been communicated to the skippers of the VOC’s fleet, the extent of the island chain was not known and they could not be accurately charted. The Abrolhos islands comprises no less than one hundred and twenty-two islands in four groups over a distance of about fifty miles, and they lie about fifty miles off the Australian coast – well out to sea.

So in 1629 Adriaen Jacobsz turned the Batavia north well off shore from the coast of the Unknown South Land. Little was he to know that out there in the depths of the Indian Ocean, the weathered remains of a coral reef still poked above the waves of high tide. Even after the events of the Batavia had been concluded and the islands marked on a map, the route was not safe. Nearly one hundred years later the Zeewijk ploughed into a different part of the island group, now known as the Pelsart group because it was assumed that these were the same islands the Batavia had struck.

Both ships ran aground at night, both lookouts reported ‘moonlight on the waves’ instead of the tell-tale surf on the reefs. I wonder how many ships actually sighted the islands as they sailed safely past in the full light of day?