Although there are more than one way of skinning this particular cat, most won't work for me because of my space constraints. I don't have room in my shop to set up uprights from which I can triangulate to the various points on the hull ...instead, I must resort to being very very careful and using a plumb bob and a horizontal grid (strings and straight edges) above the boat from which to measure:

Steps in Taking Off of Lines:

1. Set up a baseline
2. Orient boat to baseline
3. Set up a transverse reference line
4. At each station, mark and measure the horizontal half-breadths and vertical heights to each point
5. Import the offsets into CAD, create profile and plan view curves
6. Rebuild and fair the curves
7. Loft the 2D plan and profile curves into 3D curves that represent the boat, then fit developable panels to them (shell plating)
8. Check the model against a priori knowledge about the boat and unrolled panels
9. Slice the model into vertical sections
10. Export the sections in the form of 2D lines and produce the lines drawings in AutoCAD (in my case)

Note: I do the hydrostatics with the 3D model (Rhino 3D + Proteus PHASER plugin and/or ProSurf v3) but do my drafting in 2D with AutoCAD.

Shown in the first picture is the homemade water level which I used for all leveling work. For these kinds of distances, there's nothing finer than leveling with a water level. As shown in the picture, the baseline is set up so that it a) aligns with the keel from bow to stern, b) is above the boat a few inches, and c) the same distance above the level of the water in the water level at all points (see distance 'Y' in the picture.)

In the second picture, I am leveling the hull so that the keel will be parallel to the baseline. In this case, the water level had to be lowered a bit (both ends) so the reference line (top of water) was below the stringers inside the boat. The distance 'X' in the picture is the distance from the stringer to the waterline. If 'X' is the same at all points on the stringers (both stringers, fore to aft), then the stringers are level in both the longitudinal and transverse directions. This was accomplished by jacking up the building jig and placing blocks and shims under it.

In the second picture, you can see my uprights, levels, transverse reference line (aluminum straight edge), and plumb bob ready to go.

Note the following:

1. So as not to mark up my reference straight edge, I place blue masking tape above the centerline, chine lines, and sheerline upon which to mark the half-breadths
2. I marked a sheerline on the hull at a known vertical offset from the actual sheerline, which in this case isn't even built yet (3/8" above the sheer shelves is 'spec' and the temporary sheerline is 7/8" below the top of the shelves)
3. Blue tape is also placed on the hull at the (temporary offset) sheerline for marking the measuring point
4. Because hauling a water level back and forth across the boat for making the reference straight edge level would be a huge hassle, I used a normal level for this. Note that a) the level was checked to make sure it read the same in either orientation (swapped end for end), and b) both sides of the boat are measured and then averaged and this will remove any error in level
5. Offsets were measured starting at the intersection of the bottom and the transom rather than at the aft waterline as would be traditional. This is because a) the shape of the hull is defined with or without a waterline on it ;-), and b) the transom is at a 12-degree angle to the keel, so in 3D CAD later on, I can fit a plane 12-degrees off the normal and then use the boat hull panels to slice it into a transom shape ...much easier than actually measuring all points on the real transom

1. Move the uprights and horizontal straight edge (transverse reference line) to the station
2. Adjust the straight edge height so it 'just skins' the baseline without pushing it down. I aimed for a 1/16" exact gap above the centerline and included this in the vertical height measurements
3. Level the straight edge, maintaining it's height at the baseline (centerline)
4. Square up the straight edge by measuring diagonals to the other end of the boat's fairbody and moving opposite uprights fore/aft as necessary, using a plumb bob to guarantee alignment with the station mark. Note that you must measure from the same distance on either side of the centerline or else the straight edge will not be square with the hull,

Then ...

1. Place blue tape over the centerline, chine lines, sheerline, and on the sheer line marked on the hull
2. Mark the centerline on the tape
3. Using a plumb bob, place a mark on the straight edge (blue tape, black pen) directly above the inner and outer chine lines and above the sheerline
4. Place a mark on the chine lines and sheerline where the tip of the plumb bob makes contact
5. Put the plumb bob down and use a tape measure from the centerline to the marks to measure the half-breads ...repeat for the other side of the hull
6. Use a tape measure to measure the vertical offsets from fairbody, chine lines, and sheer to the horizontal reference/straight edge, both sides of the boat.

As you can see in the second photo, I had to get creative in order to get the measurements in the tight quarters in which I have to work. It shows you that you can take offsets off a hull in very tight quarters ...where there's a will, there's a way. In the photo, I have a cedar 2x4 (very straight) screwed to the wall to carry one end of the straight edge and one of the uprights has gone through the person-sized doorway to carry the other end. Because my 10' aluminum straight edge doesn't fit in these areas well, I utilized 1x3 MDF material for my straight edge instead.

The picture shows the graphed lines, raw and unfaired. These are as-is right off the boat. Once I have the lines in my 3D CAD s/w, I will duplicate them and fair the duplicate so that it best-fits the original data but is a smooth continuously changing curve with no inflections (this boat is has all convex curves, no hollows.)