Hi, Axel!
Drawing a ship just using the stations and knowing the total length is just what I did yesterday.
First I started a project for the first sketch, asking Delftship to draw just a rectangle (same length than the ship), I changed its angles' coordinates to superimose it on the vertical plane of symmetry.
Then I imported the picture as a background image and centered it according to the plane if symmetry (shown by my rectangle).
I positioned the top of the rectangle at the ship's half beam distance.
I determined the stations intervals (comparing their number and the total length), then I divided the rectangle in as many parts as there are stations.
I moved the superior angles back to the symmetry plane.
I moved the mesh angles to their position to determine the edges final position.
The draft was done. Top view and side view were loooking well.
Then I divided horizontaly into four the rectangles, which followed more or less the diagonal slicing.
And now, the most boring: I moved each point, one after other, until I got the model's stations superimposed to the background image. The problem was that when moving a point you don't change only the corresponding station profile but the surrounding stations' profiles too.
Neither the keel or the rudder were shown on the background image, so I had to guess.
Does it sound clear?