<< CHAPTER 1THE ESSENCE OF SEAMANSHIP
Some years back I was in the Hebrides in my old pilot cutter, bound for St.
Kilda. Nailed by a westerly gale, I turned back and anchored in a hidey-hole
by a small post office on North Uist. The chart showed a flattish bottom with
widely spaced soundings. I let go at half-tide with 7 feet under my 8-foot
draft, worked a swift tidal height calculation, and kissed my troubles goodbye.
After three days of damp, freezing weather our stove ran out of coal, so I
rowed ashore to meet the postmistress whose stack of combustible turf had
caught my eye. She handed me over a sackful for free while her old Mom
knitted me a pair of hairy socks. Awash in the milk of human kindness, I
pulled home to stoke up.
Overnight, the wind howled while
the moon waxed big above the driving
wrack. The rising tide covered
more land than previously, and instead
of high water bringing 18 feet,
at dawn I found 22. My half-inch
chain was now bar taut, and although
dragging her 120-pound fisherman
anchor was not one of the boat’s
habits, I surged out another 10 fathoms
anyway, making a scope of 9:1,
enough to ride out a hurricane. Unfortunately,
there remained the problem of the ebb. By breakfast it was blowing
harder than ever and the beach was showing more of its bones than I wanted
to see. We had only a foot under our keel and the tidal range was still increasing.
We bumped at low water that evening. Not severely, but I knew we’d have to
shift berth at high water, come calm or tempest. Luckily, the issue never
arose. The gale blew itself out and was followed by a stiff east wind blowing
straight into the anchorage. We banked up the fire, hoisted anchor, and beat
back across toward Skye, contemplating lessons learned.
The first was the benefit of a real stove. If we’d had blown-air heating, I’d
never have met the postmistress and her mother. I’d have burned up valuable
diesel fuel and the batteries would have taken a hammering. The second
point was that poring over charted depths would have made no difference to
my anchorage being safe one day but not the next. I correctly decided where
to anchor by relating my own sounder readings to a tidal curve to see how
much water there’d be at low tide. I added this to my draft and threw in a
clearance figure. All would have been fine except that the tides were working
up toward springs and I stayed longer than planned.
Deciding where to anchor solely on the basis of a spot sounding is a bad idea,
because there’s no certainty that the figure is exactly where you’d like to
think it is, especially on an over-zoomed chartplotter. But with a little help
from the tide tables, a properly calibrated sounder is telling the whole truth
and nothing but the truth.<< CHAPTER 1THE ESSENCE OF SEAMANSHIP