Ballast |
The amount of weight carried by a boat to provide
stability to couteract the healing force of the sails. In older large
sailing vessels this was normaly accomplished using the cargo for ballast.
On Pneuma it is the lead in her Keel |
Ballast / Displacement Ratio |
A formula for anyalizing the displacement of
a boat versus it's ballast. This is useful in determining how stiff
or tender a boat is going to be, and gives a good indication of it's
tendency to capsize should hull form stability be exceeded. It is simply
the ballast/displacement. |
Beam |
Beam is the maximu, width of the boat. |
Brewers Index of Motion Comfort |
A formula brought to the forefront of cruising
boat anyalysis by Ted Brewer. It seeks to describe the motion of a boat
at to how comfortable it is to the people inside it in heavy weather.
The formula in it's standard format is Comfort = disp
/ ( 0.65 * ( 0.7 * lwl + 0.3 * loa
) * beam^(4/3) ) |
Capsize Screen Ratio |
A formula for determining the propencity of a boat
to capsize in large seas.
CAP=beam / ( disp / ( 0.9 *
64 ) )^(1/3)
Less than 2 is considered good for a cruising boat. The lower the
number the less likely the boat is to be capsized in any given situation. |
Displacement / Length Ratio |
A formula for analysing the displacement of a
boat versus it's length. Helpful in comparing the motion and potential
speed of various boats. Derived from the formula Displacement/length
Ratio= (Displacement in Pounds/2240)/(Length
on the water line in feet/100)^3 |
Displacement (Disp) |
Displacement is the measure of the amount
of water that a boat displaces when floating. It could also be thought
of as the total weight of the boat. On larger cargo craft the maximum
displacement can also refer to the weight of cargo that can be carried
by the ship. |
Draft |
Draft is the amount of water the boat draws,
also talked about with the words: "How much does she draw".
The answer for Pneuma is she draws 6 feet. This number is usualy the
draft of the boat without any fuel water, or other supplies. Most cruising
boats out here seem to draw from 6 inches to 2 feet more than their
designed draft. |
Keel |
The bottom of a sailboat, a structure that sticks
down, normaly made of or containing lead as ballast |
Length on the Water Line (LWL) |
The measurement length of the boat where the
hull meets the water. This measurment helps in figuring out the theroitical
speed of a displacement hull. |
Length Over All (LOA) |
The total measurment of the boat from the
very front to the very back. Includes bow sprits, pulpits, pushpits,
and accesories like Davits, Dingies, Windvanes and the like. |
Maximum Speed or VMAX |
A theroitical maximum for full displacement boats.
Generaly computed by the formula VMAX= 1.3*SRQ(LWL).
As you can see the longer the waterline the faster you can go. |
Sail Area / Displacement Ratio |
A formula for anyalizing the amount of push from
the sails versus the displacement or weight of a boat. A tool to make
a guess at how fast she might go. SA/Disp= SA / ( DISP/
64 )^(2/3) |
Sail Area |
A measure of the surface area of the sails on
a boat. The usual measure is taken with a Genoa, not the spinnaker.
Pneuma's Spinnaker's sail area is larger than the whole rest of the
sails sail area combined. |