NavList:

Thanks to Robert Eno for clarifying a few matters.

That the event he reports was in Frobisher Bay. And-

| I may have mislead you by talking about a wildly spinning compass.
What was
| happening was the compass card was veering by as much as 60 degrees
with the
| slightest alteration of the helm. As I said, fog is not something
new to me
| so steering a compass course with low visibility is not something
which I
| normally have difficulty in doing. Except on that particular
occassion. I
| kept trying, doggedly, to steer by compass but when that finally
failed, we
| hugged the NE shore and used the radar. We also had a GPS unit but
we
| steered mostly by radar.

Ah. I had thought Robert meant it was spinning in circles, but that
puts a different complexion on it.

Just a thought about another possibility. I know little about
Frobisher Bay, but wonder if there might be strong tidal currents
though the channel he refers to. His experience sounds uncannily like
one of mine.

The English Channel tidal currents can be strong, especially off
headlands. One headland in particular, near my home port, St Alban's
Head, has un underwater ridge running out from the point, athwart the
tide. No hazard in itself, but it does powerful things to the tide.
The bottom-current is deflected upwards to join the surface current in
a series of whirlpools and kelds. When wind's against tide, it can be
a fearsome spot, but even at other times it does strange things. The
whirls twist the boat about, and I have found the need to work hard at
the tiller, putting it hard over one way then the other, to keep the
course reasonably straight.

Only once have I passed that spot in thick weather, when the headland
itself couldn't be seen, and steering was entirely by compass. It's
obvious when you get into the race, from the roughness and the kelds,
but also, because the compass heading started to zoom about, just like
Robert described. If I hadn't been familiar with that passage, I might
well have attributed it to compass problems, but indeed it was the
result of the wish of the boat to point anywhere but where I wanted it
to go. The compass was telling the truth. Fighting those swirls took
me through.

Is it possible that was happening in Frobisher Bay? I recall reading
accounts of Hudson having that sort of problem in Hudson Strait, and
Davis, just off Resolution I., but Robert's experience was at the
entry to the upper bay, where the currents might be much weaker.

However, now we know it was in Frobisher Bay, the other hypothesis,
about magnetic disturbance, shows more promise. It took its name from
Martin Frobisher, who in the late 1500's claimed to have discovered
gold, and shipped back to England hundreds of tons of what turned out
to be "fool's gold" or iron pyrites. In the end, it was used for
surfacing roads. Could there have been such a deposit, under the
channel that Robert was passing through?

George.

contact George Huxtable at george@huxtable.u-net.com
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.


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