Offsets

A digital representation of a station drawing can be stored as a series of offsets.

To reproduce (loft) the station drawing, a large piece of graph paper is used. Points are identified on the coordinate system and marked on the graph paper. Because of the complex curves of the cross section, at the station, offsets are normally listed for various measurements above and below the waterline, and a separate set of measurements are made lateral to the centerline.

For a typical station, there may be measurements available in the offsets from 10 inches above the waterline to 4 inches below the waterline. Also two measurements for values from 0 inches off the centerline to 12 inches off the centerline may be available.

Such a set of offsets are available in The Strip Built Sea Kayak for three strip built boats. A list of the offsets (mainly meant to correct several measurements at error in the first edition of the book is listed below. If you want to read the measurements easily, buy the book! It also has a great description showing how to loft out the forms from the offsets.

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