A lot of those carpets are bleach resistant. Try a little bleach some place
where the carpet doesn't show and see. Bleach will reduce the intensity of
the stain even if it does not remove it.

"Michael Bushey" wrote in message
. ..
My 15 year old boat has black patches on the indoor outdoor carpet. It
appears to be old mildew. Vinegar and baking soda didn't touch it. Carpet
cleaner doesn't work. Any suggestions appreciated.