@Ian,

Thx for your reply, looks as if there is no easy way to get the result I want.

Have found a way, more or less as you say, by manipulating points.

To illustrate wat I've done sofar (it's not a worked out model, I'm just trying to find out how to do surface modelling with this software), a few screenshots are attached to show the method I used to get my cambered deck.

Background info, my starting point is the bodyplan together with the table of offsets of a multi-chine launch of appr. 9.00 (L) x 3.00 (B) m.

The camber in the maindeck, at full B, is set at 60 mm with a circular arc as profile; segment heights at buttocks 0.5 and 1.0 m can easily be calculated to get the decheight at these points.

What I did:

step 1) imported (as surface) the offsets of 3 frames, see pic 1,

step 2) created a deck by extruding the deck at side edge and entered the co-ordinates of the 3 points at the inside deckedge as given in my offsets for deck at centerline, see pic 2,

step 3) splitted the 3 transverse decklines (twice each) to get additonal control points and entered the (calculated) co-ordinates of the points at the buttocks,, see pic 3.

result: see pic 4, looks like a nicely cambered deck.

A long way to get there, an easier way might be by adding control points ("in space") with the co-ordinates for the deck and then creating a new face.

Jasper