During December 2009 you can purchase The Boating Bible Manual of Seamanship for only AU$156 – a 20% discount off its advertised price. This multimedia Manual contains the five titles listed below, plus you receive a free bonus 75-minute DVD, The Joys of Sailing.
First, for those people who don’t know what scend is, here is a definition:
Scend is the distance from sea level to the bottom of the trough of a wave. The trough can be taken as being equal to the height of the wave above sea level, or more simply as half the height of the wave. This means that, with a 3m sea running over a bar, the depth available to you may be 1.5m less than you would have in a flat sea.
So how does a navigator deal with it? You need to think of the charted level of the sea, the average height of the waves and swells combined. To this you add your calculation of the relevant state of tide and estimate the scend with the above definition in mind. Call that ‘A’.
‘B’ is the depth of the keel and the amount of scend. Subtract ‘B’ from ‘A’ to get ‘C’. If ‘C’ is negative there isn’t enough water. Even if it is positive there has to be a reasonable safety margin.
Then, depending how frightened you are, add a second safety margin. Call that ‘D’.
A blog alerted me to the term ‘frostbiting’ – sailing in winter – and my curiosity was aroused. It’s not to be confused with iceboating, where hulls are fitted to ski-like runners and can get up to 100 mph off the wind. No, frostbiting would seem to be for people who don’t feel the cold! Boston harbour is one place where intrepid (or should that read foolish?) sailors pull on many layers to look like the Michelin man so that they can enjoy a few hours on the water. And one of the yachts that race is the Laser, on which you can expect to get wet!
Here in Sydney we’re fortunate that the temperature in the coldest month (July) only drops to an average 16.3°C /61°F. Even so, there’s always a great buzz back in the bar as competitors warm up again after a race.
A. A paralympic sailor.
B. A yacht with two identical masts and sails.
C. A spinnaker with a vent system that provides greater stability than a traditional spinnaker.
The video has given the answer away – it’s C.
The Parasailor, a German innovation, was written up in Yachting World in “The Best Way to Sail the ARC”:
“It is a spinnaker with a vent and is said to be better mannered than a traditional version and can be set with or without a pole.
“With the vent, it will tend to allow the wind to blow through, so gusts will have less of an effect and it will provide added stability.”
Time will tell whether the idea takes on. What do you think of it?
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In The Boating Bible Manual of Seamanship – Boat Handling 1 – we show how to use twin headsails to keep the boat stable when running.