Stain on hull.

[K9Kampers]

Headline:
Blue hull portal to H3LL requires :macx:orcist!

[Bransher]

[Catigale]

orcist, shirley....

[bobmonroe]

Sno Bowl toilet cleaner can be found in most grocery stores.
Test small area first.

[vizwhiz]

Hey bransher...do you have ghecko's? Lizard poop is usually small and two-colored (white/black), but ghecko poop - it's usually long and runny and sticky.
If you have ghecko's running around in the shed at night, you might have ghecko poop sliding down and not sticking to the waxed gelcoat, but staining the bottom paint...same idea as the rust. Tree frog is another option. You might have one that found a comfy spot up there and stays put on top of the channel most of the time. Is there a light nearby that stays on at night that might attract bugs? Might be worth a ladder trip...

Okay - it was a long shot, but my technical head says it's more likely something like rust or oil or something...but I couldn't rule out animals...this is Florida, y'know. Heck, it could be a big spider for that matter...you have any of those up there in the ceiling?

So Is that the only place it is on the boat?

[Tide Over]

In my opinion your boat was subjected to some sort of agent in the water when you probably last sailed her. The agent was most likely a grease like substance which adhered to your bottom paint but not the gunwhale finish. Think of it as a gucky somewhat diluted tar based substance (like that in the Gulf of Mexico stuff still floating around) it does dilute over time but usually very slowly depending on the density of it at the time it stuck on your boat. It obviously was able to adhere to your bottom paint and is slowly diluting and running down the side of your boat. Any kind of moisture in the air or directly applied will speed up this dilution process. Note how it lightens (dilutes) as it flows downward. I'm quite sure that when you get rid of it the problem will go away that is unless you take her back out and run into whatever that stuff was that stuck to your boat in the first place.

[kmclemore]

[non_sequitur]

Every time I look at the title to this thread I think it's referring to some small village in Middlesex, England. Go figure.

[/non_sequitur]

[Catigale]

All roads leed to Hull, surely...