. I decided to run a contest. I will mail a free Dungeness crab to the first person to correctly identify that strange pink staining on the bottom of my RIB. Left it in saltwater for a couple of weeks and it wasn't pink when I put it in the water. The stains are below the waterline, so it's not from dye in any fuel. Any guesses?
What Peter C said, its coralline algae. A weak acid like vinegar can help loosen its bond to the hull/tubes. Tackling it wet is better than dry, its pretty tenacious when dry. You might put the hull back in the water for a few hours before scrubbing with vinegar and a green brillo pad.
Thanks for the replies. I don't normally leave the RIB in the water for any length of time and I'm a former prairie boy, so have never seen anything quite like it. I did ask some of the local salts around here and no one had any suggestions as to what it was. One thing that threw me off was the fact that there doesn't appear to be much of anything on the surface of the hull or tubes. It just looks like a stain and it seems to be well attached to the gel coat. I tried some sea power inflatable boat cleaner and with some elbow grease it works on the tubes, but not very well on the gel coat. Will try the vinegar.
Scubaqua
