Just purchased a new sailboat and discovered what looks to be an
accumulating white powder at the base of the head sink drain thru-hull. It
is almost growth like and has greenish specs in it. Not sure if it is from
a leaking drain hose causing some sort of mineral deposit. The surveyor
said he did not know what it was but did notice some seepage around the hose
area where it attaches to the seacock. Knowing what this might be before I
clean it up would be a helpful.

Thanks,
Bob