VTW

True wind speed

Beta (β) TW

Course relative to true wind

Spinnaker

Whether the spinnaker is set (up) or not (down)

VAW

Apparent wind strength

Beta (β) AW

Apparent wind direction

Hull Speed

Speed of yacht

VMG

Velocity made good to windward (+ve) leeward (-ve)

Heel Angle

Equilibrium heel angle of yacht

Fwd Force

Drive force produced by sails

Sideforce

Side force produced by sails

Reef

IMS Reef parameter, a value of less that 1.00 indicates that the optimum sail size is less than the total available sail area.

Flat

IMS Flat parameter, a value of less than 1.00 indicates that sail coefficients, less than the maximum available, are optimum.

Form Drag

Main drag of hull and appendages

Ind. Drag

Induced drag of appendages

Aero Heel Moment

Heeling moment due to sails

Hydro Heel Moment

Heeling moment due to appendages

Hull Right Moment

Righting moment due to hull weight

Crew Right Moment

Righting moment due to crew weight

Force Err

The VPP algorithm balances the forward drive force against the hull drag. After the maximum number of iterations, any error is given here.

Moment Err

As above but for the heeling/righting moment balance.