I'm finishing up a Wood Duck from plans (previously built a Shearwater from a kit).  I used the transfer paper roll as you are considering (blue seemed to be a good color for the wood - easy to see) and I thought it worked well. The roll I had wasn't wide enough for some of the pieces, but I taped the plans down at several spots and carefully shifted the transfer paper underneath as needed and it was fine. 

I did butt joints with fiberglass tape on my plywood instead of scarf joints and they held up fine.  I wasn't up to messing with the scarf joints/tricky angle cutting.  I did the butt joints on full width plywood (4 x 8), but you will need to do 3 sheets so it will of course be trickier to handle. 

Before cutting anything I laid out my patterns on the plywood to make sure everything fit.  I would suggest doing this before you cut anything, particularly if you are interested in keeping one side of the panels on the outside of the boat (in case there's a side with poor grain or something).  I joined the panels with the butt joint and then traced out all the patterns and then cut the panels lengthwise so I could double them up and cut the mirror image pieces together (used the stitch/hot glue method described here and it went really well (http://www.oneoceankayaks.com/stitchglue/plyshophtm/platecut5.htm).  Note that for my boat the lengthwise cut was at a diagonal angle, so cutting the pieces into 2 foot widths prior to joining the panels would not have worked.  That's why I did the layout first (and I also cut out some of the shorter, wider pieces from the panel prior to the diagonal cut). 

Have a fun build!

Kathy

Transfer paper is by far the best way to mark the plywood, but you don't need a huge roll. A single sheet of carbon paper will do it - just keep moving the sheet along. I did this with two boats and it works fine.

As for laying out the parts on the sheets, don't be afraid to lay them out differently than suggested by the designer, if that helps to fit them on a sheet.

-Wes

Topper-

This is how I have built 2 Shearwater boats from plans [there is the right way & then there is my way]

1. Build 2x16 table with 12" grid lines horizontal & vertical.

2. Use the straight edge of the plans to give reference points at 12" increments on the plans.

3. Cut the plans into usable strips.

4. Transfer the plans onto the 4x8 Oakume sheets using old fashioned carbon paper lining up to the grid marks. ADD CORRECTLY for the scarfs.

5. Cut out sandwiched Oakume sheets

6. make scarfs and glue up matching the grid lines on the table

Timely but accurate

Lew

*Newbie Paranoia Alert*

I have all my lines transferred to the plywood and ready to cut. The plan lines are pretty thick, I traced the lines using the very outside edge of the plan lines, now I am wondering if the lines were meant to be taking or left when cutting. I have heard that the SW has a low tolerance for variation (1/16 inch) If I cut leaving the line this could add as much as 1/8 inch overall to each panel if it was not designed that way. Wondering what others have done.

Thanks,

Harlan