Skipper599 wrote:
Your comment about scribed lines at the waterline are certainly valid ... my hull happens to be fibreglass and so, I put my faith in the moulded gelcoat W/L ... but this still required I find a way to actually level the hull, not only fore and aft, but also athwartships ... I eventually used a garden hose, to which I attached a 12" length of clear plastic hose to each end, taping them to straddle the waterline. First, fore and aft, and then athwart. ... I mixed up a gallon of colored water using food coloring, filling the hose from one end with the aid of a jug and funnel.
The use of a water level when done carefully as it certainly seems you have is extremely accurate. I would feel quite confident in what you have done.
Skipper599 wrote:In addition and for reference only, I hung a plumb-bob from a central point in the cabin ceiling, about 6" aft of the main bulkhead, measuring to find it actually hung parallel to the bulkhead and also centered on the cabin sole. Of course, that could have been pure luck.
It was probably skill on the part of the builder, but I would never use this to establish level until I had proven by another means that the boat was level and then did this test. And even so, it isn't as accurate as using the original water line and your water level.
Skipper599 wrote:Not completely satisfied, I set a Laser level over the mast step mounted on the cabin top, and then took measurements down to the W/L, all of which came within acceptable figures (eg:within a 1/16" ) to assure me the boat was as level as was humanly possible.
Hmm, I'm not sure that this information tells you anything except that the top of your mast step is parallel to your water line. If this is so, then in the future you can use your mast step to level the boat, but again, I don't think this is as accurate as you water level/waterline method. But to say this assures you of anything else would be a mistake.
Skipper599 wrote:Oh, yes, I also set a carpenters level across the main hatch rails and found it was level also ... again, possibly pure luck?
Maybe luck, maybe skill, but either way it doesn't verify anything. You don't even know if it was meant to be level.
All of your secondary measurements may offer you some peace of mind, but your first method was the best. And it seems that your boat was layed out and built to a much higher standard than most.