Get hull sonogram when the boat is surveyed. A surveyor who is
knowledgable about steel hulls (and you might consider a commercial/
industrial surveyor, not a yacht surveyor) will know this without
being prompted.


Jere Lull wrote:
Unluckily, I had experience in an industrial setting with this.... He
reported a section of pipe as being full thickness (1/2") about a day
before it blew out. It had to be paper-thin.


Hmmm... now that you mention it, I've known that to happen too. But
that doesn't invalidate the method.... it's technology, not magic!

Make sure the guy can *find* thin metal!

Another PITA was that all paint had to be removed before the reading
could be made.


The instruments I'm familiar with will read thru paint, but the paint
has to be bonded and uniform thickness. You have to have a test
section that is known to be sound & up to spec.

I'm not sure a better method wouldn't be to "sound" the hull with a big
hammer, or maybe a small pickaxe.


Sure. Any place it leaves a dent, you know the hull isn't thick
enough

DSK