T&T: A New boating problem

[Anne Reeves]

We have a 45' Puget Trawler which we haul out every year for maintenance. 
Last year and then again this year, there was about 1/16 inch of a hard 
saltlike substance over the whole stainless steel shaft.  Not on the prop or 
anywhere else, but all around the shaft.  It is hard as a rock and very 
difficult to scrape off.

Last year, the boat two slips down from us hauled out and had the same thing 
happen to their shaft.  They will haul out again in a week so I do not know 
if they have the same thing on their shaft this year.

Two years ago a different powerboat moved into the slip between our two 
boats.  We thought there might be some stray electricity or something coming 
from their boat.  The Port supposedly checked the water and said there was 
nothing wrong.  It is curious that our two boats both have the same stuff on 
our shafts. The boat on the other side of us has been there for 20 years and 
we never had any problems.

Has anyone ever heard of this?  Does anyone have a suggestion?

Anne on SEABIRD
45' Puget Trawler
Port Townsend, WA