Drawing on experience
There’s more to the humble hydrographic chart than meets the eye.
There’s more to the humble hydrographic chart than meets the eye, and its origins date back centuries.
Amarine chart is no mere piece of paper. On one level it may be a map of a designated stretch of coastline – or ocean – showing depth contours and sea floor features. Properly used, it can save your life – or prevent drastic damage to your boat or crew. But on a more fanciful level, a chart also does great service spread over a kitchen table to plan next summer’s cruising itinerary while winter gales thrash around outdoors.
A chart – calling it a map will earn withering scorn from navigation tutors and experienced seafarers – is the culmination of painstaking survey work and a long tradition of navigational excellence. One of the hardest chartwork lessons can be learning to place your entire faith in a piece of paper – but they’re rarely wrong.
If someone tells you they hit an uncharted rock – it normally means that they didn’t know where they were on the chart. Having said that, I once had a close call with an isolated rock off North Cape, which was on a fold in the chart. The chart had been folded so many times that the rock had been obliterated – it was time to buy a new one.
In this age of relatively cheap and accurate GPS chart plotters the paper chart is at risk of becoming redundant – but there’s great satisfaction to be had in plotting your own position on a chart and keeping the skills alive.
You also get to use those nice navigation tools; well-worn bronze dividers and parallel ruler, a hand-bearing compass or course plotter, a 2B pencil (easier to erase) and rubber. Precise chartwork is draughtmanship of a high order.
“You can’t trust electronics at sea – electricity and salt water don’t mix,” the old hands used to grizzle. But modern boats are
generally dry inside and don’t drizzle through the deck like their wood-planked forebears often did in a seaway, and modern electronics don’t fizzle up and go fatal at the first whiff of salt water like earlier models did.
It’s pretty common these days to have four or five GPS receivers aboard – phones or hand-held units and ipads included – but it also pays to have a chart aboard to plot the fixes they relay. There’s a story around about an American yacht en route to New Zealand who paid for a RNZAF Orion to divert and tell the skipper his position over the VHF radio. His GPS plotter had died, and he hadn’t plotted a fix in the preceding four days. That gives a whole new meaning to ‘lost at sea.’
But charts can be compromised by liquid too. A friend once spent two days hove-to outside Port Vila waiting for another boat to arrive so he could follow it in because a cup of coffee