The zero point is the reference point that all measurements are taken from. You may choose the position of the longitudinal zero coordinate by selecting from the available options:

Forward Extremity.

The forward most point of all existing surfaces.

Forward Perpendicular.

This is specified in the Frame of Reference dialog where it may be automatically positioned at the intersection of the design waterline with the bow.

Amidships.

Midway between the fore and aft perpendiculars.

Aft Perpendicular.

This is specified in the Frame of Reference dialog where it may be automatically positioned at the intersection of the design waterline with the stern.

Aft Extremity.

The aft most point of all existing surfaces.

The vertical position of the Zero Point may be set to the Datum Waterline or to the Baseline. The positions of the forward and aft perpendiculars, Datum Waterline and Baseline are all specified in the Frame of Reference dialog.

The forward and aft extremities are recalculated every time you change the design. If you have used either of these points to define the longitudinal position of the zero point, then the zero point will move as the design is changed unless it is locked. Even if locked, the zero point will be recalculated if you set the frame of reference again.

The Zero point is always displayed in the Plan, Profile, Body Plan and Perspective Windows as a small vertical cross.

Also see:

Maxsurf Coordinate System on page 36.

Setting the Frame of Reference on page 36.