Yesterday when coming back in to the ramp I apparently ran through a large line net just outside the pocket of where Harrison Bay ramp is located. This thing is not marked. I felt a slip in what felt like my prop and shut it down immediately to see if I hit something, but I was running in like nearly twenty feet of water. Stopped and looked around and seen the net with a small green colored float on the end. There is no way of seeing this net with any type of chop on the water, which was the case yesterday afternoon. I trimmed up and didn't see anything wrapped around my prop, but I got concerned when I got back up on plane and got up round 40 mph I felt another small slip. Just be aware of this net and I really hope that my motor is not damaged in any way. I come here about five or six times a year. I didn't realize that people could do this- particularly in a high traffic area of the lake.