Checking the weather

Practical: Back to Basics

Skipper's checklist

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Any checklist aimed at trouble-free cruising is based on endless preparation, and real preparation should never be based on electronic dependence. The old truism of, "Today's luxuries are tomorrow's necessities" must be balanced by Robin Lee Graham's simple observation that "At sea, I learned how little a person needs, not how much."

Regardless of personal priorities in the planning, it all amounts to nothing if a cruise starts in inclement weather. This seemingly unnecessary observation is based on the fact that many new and not so new sailors appear to have little to no regard for offshore conditions on departure day - some even blithely sail straight into a forecast gale! If not out of ignorance, then I suspect such behaviour can be sheeted back to that hard-to resist human condition known as "impatience".

Shattered dreams
Impatience is the mother of impetuous decisions, which all too often leads to the utter destruction of long-cherished dreams. Cruising is littered with shattered dreams and failed relationships caused solely by absurd decisions made on departure day. Irrational deadlines seem to become more important than the sum of all the work and money that went into reaching this significant moment.

Short-term cruises are the most vulnerable to this syndrome for the obvious reason that schedules are tighter. Yet, unless you and your crew are immune to mal de mer and the abysmal discomfort of a small craft being thrown around like a cork in a washing machine, the risk of instant disenchantment prevails. You may well be obliged to abandon the cruise after your family or crew abandon you.

Departures based on their advertised day rather than on weather conditions have no place in the great scheme of things. Such intractability is as dumb as it is dangerous and if a farewell party is held the night before, then do everyone a favour by sailing no further than around the nearest headland, there to drop anchor and await suitable conditions.

Wind and waves
Wind direction and wave height forecasts are available from many sources, including newspapers, television, land and mobile phones, VMRs and the internet. The trick is not to accept any one source as gospel; instead, study them all and look for anomalies. It is surprising how contradictory they can be, a seven-day wind and wave prognosis recently promising northerlies every day despite the synoptic chart showing a strong southerly surge in two days time. The chart was right, as usual, reminding us that the mother of all forecast tools is the synoptic Presented intelligently, television weather is one of the best ways to see and comprehend synoptic charts. Weather predictions are based on the immutable fact that winds blow anti-clockwise around high-pressure systems and clockwise around low-pressure systems (vice versa in the northern hemisphere). These same winds also migrate from highs into lows, meaning that their true direction is slightly angled out of highs and into lows. Actual wind strength will vary according to pressure gradients between systems, the steeper the gradient the stronger the wind.

Low-pressure system
A low-pressure system in your vicinity may produce strong wind, rain and rising swell and could conceivably deepen into a severe gale or cyclone. Lows need close monitoring, preferably from the security of port. Troughs should also be treated with susHighs, on the other hand, can be too friendly, denying you a reliable wind other than an afternoon sea breeze. However, a high over the sea promises low swell conditions and if a ridge forms towards the land, a reliable and often boisterous wind results, sometimes accompanied by scattered showers as moisture feeds in from the sea. These showers may be preceded by the wind backing (shifting anti-clockwise) slightly and strengthening ahead of the rain then easing behind it. They are not very threatening, but any and all low cloud masses to windward, regardless of their source, should be treated with suspicion.

Excessive caution
Fear or litigation since the 1998 Sydney-Hobart tragedy has marine weather forecasters tending towards excessive caution, to the extent that there is a risk of crying wolf. Strong wind warnings tend to be over-stated more often now days than in the past: nevertheless, when planning a departure date, presume the worst, not the best.

With experience comes the sort of seat-of-pants weather-awareness that is difficult to pass on, but a fundamental understanding of wind circulation around high and low systems clarifies direction and steep gradients between isobars carries the threat of strong prefrontal, then frontal winds. A synoptic chart paints this But remember, whether experienced or not, the real enemy of a successful cruise is impatience and this should not be on any checklist.

AUTHORS BIO
Alan Lucas is Australia's leading cruising writer. Skipper's checklist will be a regular CH.