A In a wooden boat, apart perhaps from the garboard (the strake alongside the keel) you don't caulk clinker planking. The lands (overlaps between adjoning strakes) must be made carefully at the correct angle, which varies constantly anlong its length. The rivets hold the strakes together and the lands should seal themselves when the boat becomes wet in use. If the building job has not been done well enough for this to happen, you are in trouble. In case someone does not know what a strake is; a plank is not quite the same thing as a strake but gives the general idea. Caulking an iron vessel is done quite differently from the method in a wooden one and I suspect that this was done, though I have no direct experience of it. (  )