Planking, looking at the men's heads in the dry dock sizes up the planks to be about 1ft wide.
Need to divide the frames with no planks more than half an inch, slightly over scale but this will only be at the widest frames. First rap a strip of paper over half a frame mark the distance, repeat on all frames. The widest frame (5)in this case will need 14 strakes at least, fitting an A4 paper, mark 14 half inches starting central 7 each side. The smallest frame (1) will need 3/8th to cover it. Surprisingly little difference really. So mark 3/8th marked at the bottom of the paper. Join the marks, place the strip with the distance marks square across with the measurement touching the outer marks, draw a line mark the frame number. From this the divisions, transfer to frames. I start with the garboard strake & the top strake working to the centre. May not stick rigidly to the spacing, if going under stick a wide one in, or thinner as the case may be.
I make my own planks, rip down on bench saw, thickness them by pushing under a roller on an upturned belt sander. Always push against the rotation of the belt, other wise it will snatch 7 take fingers.
By to days standard 1ft planks are very wide, but I do have a pitch pine flooring board 11in on my bench. Taken out of a grain store 60 years ago.