I really 'cheated' when I planked the deck of P.S Industry.

Firstly I cut the planks to size in long strips of about 500mm,
then I glued them back together using Epoxy Glue with a little black paint
( just a few drops will do ) mixed in.

Laid them up on grease proof paper and clamped together to form nice
laminated boards about 100mm wide x 500mm long. Then cut to fit on the boat.

Worked well and very easy.

( I dont like the ink pen lines method as I JUST KNOW that the pen will slip
on the LAST line !! :-)