To calculate geometric characteristics of the hull using numerical techniques, the information on the lines drawing is converted to a numerical representation in a table called the table of offsets.
The table of offsets lists the distance from the center plane to the outline of the hull at each station and waterline. This distance is called the "offset" or "half-breadth distance". By convention this is the "y" direction. The table also lists the heights at different buttocks and stations.
There is enough information in the table of offsets to produce all three plans of the lines plan.
You may need to use the table of offsets when you are asked to calculate one of the geometric properties of the hull such as sectional area, waterplane area, submerged volume and the longitudinal center of flotation. Source
How to use the app
The app is able to read a table of offsets and plot the lines plans and a 3D view of the hull. In order to do so, both the half-breadths from centerline and heights above baseline files should follow the examples shown below. Do not forget to save the files with a .csv file extension.