Rowing Reporter

The Rowing Reporter is a weekly column of commentary and
observations by Ike Stephenson, Marine Informationist. It
concentrates on the home waters of Around the World of
Sailing, Lake Michigan and Muskegon Lake.
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I decided some time ago to write about STD and it's relation 
to sailing. More recently I realized the closeness to STD's 
as in sailors on leave, training films etc. For the purpose 
of this column, we can drop the 's and just concentrate on 
STD.

STD is an abbreviation for Speed, Time and Distance. STD is 
both a mathematical equation, and an interdependent 
relationship that strips sailing to it's essence.

The equation works as follows. To solve for speed, take the 
distance and divide by time. To solve for time take speed 
and divide by distance. To solve for distance take the 
speed and multiply by time.

Speed and sailing have increased throughout the years. 
Columbus barely averaged a knot (.83) to be exact on his 1492 
ocean blue voyage. The most recent mark for the 24 hour 
sailing record is 29.04 knots. No question the 'S' portion 
trends it up!

We can get a further look at speed in another mathematical 
way. If you drop an object from a bow of a ship and time 
how long it takes to get to the stern you can determine 
speed. The relationship is 1 foot per second =.5925 knots. 

Time is the second element. Time is somewhat dependent on 
the speed and the distance to be covered. Certainly time has 
a different meaning to a weekend cruising sailor and a 
Clipper Ship captain. The cruisers time is delineated 
within the midst of other needs and desires. To the clipper 
captain it's a matter of how much time it will take to do 
the job.

Distance is the third letter of the abbreviation. How much 
distance you cover is again a bit dependent on speed etc. 

It should be noted that in many ways distance has not 
changed. If you look at many of the classic offshore races, 
Chicago to Mac, Bermuda Race, Sydney Hobart etc. while speed 
has increased and the time spent on course decreased the 
distance is unchanged. While the potential to have a longer 
race is there, sailors have chose not to do so.

Another bit of math can help us learn more about distance. 
After sailing at a given speed for some time, hopefully 
we'll near our end point. How soon should we expect to see 
land, the home light etc.? 

By taking 1.15 and multiplying it by the square root of the 
height of the eye you can determine how far off the horizon 
is. Then depending what you are looking for you can know if 
the end is in sight.

While very useful, STD is not a comprehensive way of looking 
at sailing. Surely what helps determine the speed etc., is 
wind.

One way of determining wind speed is the Beaufort Scale. 
This can be seen at
http://www.torresen.com/weather/weather/beaufort_wind_scale/?keyword=sailboat.
A quick way of determining what the relationship between 
force and windspeed is another equation. Take the force #,
for instance 7, subtract 1 and multiply by 5. For instance 
7-1=6*5 is 30 knots. Or 4-1=3*5=15 or force 4. Certainly 
wind is on an equal level or perhaps above ST&D.

Finally, when I first began sailing, boats often had simple 
rotary analog speed time and distance calculators. You 
manipulated the machine to input the known elements and were 
give the third. 

Now most all boats have GPS in one form or another. All will 
tell you the speed you are making, distance to waypoint and 
your time of arrival. GPS can be seen
as the next stop in STD calculators.

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