Floating lines are killers. Markers with additional pick-ups sometimes 10mts away with a floating line between.

Pots marked with large enough buoys are fine, preferably with weighted lines or the lead cored line that is available. Flag markers are good too if tall enough and NOT as an additional pick-up to another buoy with floating line between.

Old chemical cans, ball valve floats, fenders etc are a definite no no, very difficult to see and probably not belonging to any pro fisherman

Location. I know they are put where results are expected, but harbour entrances and entrances to channels should be out of bounds.

What are the CG or RNLI figures for assistance given to boats disabled by lines round propellors or rudders?