Recently a surveyor friend in Newport, RI sent me some photographs of some standing rig fittings he had been asked to give an opinion on. The boat was a rather large Oyster ocean going sailing yacht and the issue was that someone had inspected the boat for insurance purposes and stated that all was in good order. The owner of the boat was wise enough to get a second opinion, and so was my friend the surveyor, he asked my opinion. The photos below show some of the fittings.
So, to help the uninitiated here, what you are looking at is caused by crevice corrosion, a topic I've discussed on this blog before, but is certainly worth more discussion based on this case. Crevice corrosion is pretty exclusive to stainless steel alloys and is caused by salt water exposure in an oxygen deprived environment.
In this case the the fittings you see are out on deck, and connect the cables that hold the mast upright on this boat. The boat gets expsoed to salt water spray constantly when underway and some of that water migrates down the multi-strand wire rigging you can see in the upper photo and enters into the barrel of the fitting that secures the end of the cable to the boat, where it gets oxygen deprived. So, what you are looking at is corrosion that began on the inside of the barrel and has managed to corrode all the way through the metal shell of the barrel to the outside of the fitting, severely weakening the strength of the fitting.
Let me keep this simple, the insurance evaluator in this case was incompetent. What you see here is a potentially dangerous situation that could easily be the cause of the mast on this particular boat falling over in a heavy wind situation, when it's all loaded up to maximum strain.
The bottom line? The owner here was wise to think of the situation in medical terms. You don't like what your doctor tells you? Get a second opinion, and if necessary a third. Sometimes your gut feelings are the best feelings. You see rust on stainless steel........ask yourself what is or could be happening and deal with it sooner than later.