multiple scum lines on one side of my boat?
 

Guys,

What causes multiple scum lines on the side and stern of a boat? My boat shows a waterline then it has a couple of other "dirt or scum lines" above the waterline. These lines are only on one side of the boat. The stern shows a line that that is very close to the waterline in the center of the boat but gets farther away from the waterline as you get out to the sides of the boat. On one side of the boat there are 3 discinctive lines on the other side it has only the algae or waterline. Why 3 lines on one side and only onle line on the other?

Re: multiple scum lines on one side of my boat?
 

Perhaps the side with multiple lines in on the windward side and the waves push the like up higher. When wave conditions change a new line may be then started. Another possibility is that there is water in your bilges that gets sloshed to one side when a big wave hits thus altering your lateral CG.

Just some thoughts....TJ

Re: multiple scum lines on one side of my boat?
 

When you talk about the waterline on the back of the boat, I'm reading it as a "V" marking with the low point of the V being the center of your transom, that tells me that the boat is leaning over from side to side for some reason. I would also agree with the above statement stating it may be from the oncoming waves caused by other boats or wind maybe??? Any water in the bilge? Slight leak causing it to lean, then it gets pumped, boat comes up, fills and leans again???

Re: multiple scum lines on one side of my boat?
 

My guess is if you have two engines, one is running richer. If a single engine, perhaps a dead cylinder on one side. :cool:

Re: multiple scum lines on one side of my boat?
 

OK guys I did not properly describe the situation, but I think the answers you gave still apply. The boat has one water line where the algea forms. This is evident on both sides and around the stern. It is level for the most part, it may be an inch lower on the starboard side. The lines I am wondering about are on the starboard side and stern. The port side of the boat only shows the algea line. The port side is in the shadows, the starboard side faces the waves and sun.

If there was water in the bilge that forced the boat lower in the water wouldn't that show up on the algea line? Any new ideas?

bbcngineer

Re: multiple scum lines on one side of my boat?
 

simple wave action

Re: multiple scum lines on one side of my boat?
 

Is it tied to the dock on one side, making it go on a kilter as the tide changes?