Interesting topic. I live and sail on Cape Breton Island. We have crab and lobster
fishing, lots of it. Lobster is an intense 2 month season, may 15 to july 15th where i live. Fisherman here use 1 line/bouy for each trap. There are loads of them inside my home harbour, but when you get outside they are a lot more dense than the video someone posted of
Maine.
Despite the effort i put into avoiding them, I've snagged traps a number of times, usually between spade
rudder and
hull. I've also had several prop wraps. On my previous
boat (hunter 33) i always managed to clear things without going into the
water. Prop wraps were soft (saw the lines last minute, into neutral, so freewheeling when wrapped) so a little reverse once we had one end of line in hand freed it. To free it from
rudder, used boathook to pull up trailing line (moving at a few knots towing trap). Cut line, hold both ends, use boathook to grab bouy, pull free, retie so fisherman can retrive trap should he find it at new location.
Note my courtesy to fisherman. But as I get older this wears thin. Here' s why: fisherman in our area use cheapo floating
rope. They tend to
fish deeper early in season and progressively move inshore. Most (the vast majority) are too lazy and incosiderate to shank their lines. Thus sometimes you see 50 to 100 feet of line floating across the surface, creating a nearly impenetrable maze just waiting to snag any unsuspecting boater who crosses them. (one exception, in one small harbour the fisherman all agreed to use sinker line which poses very little hazard. very considerate and probably a good economic decision for them)
So i respect the comments from those who respect fisherman's need to make a living. But fishermen really should respect each other, pleasure craft, whales etc by using sinker line. An appropriate place for regulation (??? can't believe i'd suggest such a thing

)
Defenses:
- I never tried a line
cutter. Wouldn't be opposed but not relevant on my present
boat.
- on my present boat (Gemini 105mc) I machined two
aluminum wedges and epoxied them to the
hull just ahead of rudder. So if i cross a floating line, the line is deflected downward onto the leading edge of the rudder, so it doesn't foul in the slot. The float eventually catches and the pressure makes the rudder pop up as designed. This has worked like a charm and not i don't worry about sailing over lines. This also sort of protects the prop as the
gemini driveleg is behind the rudders, but obviously this is not complete protection. So I'm still extremely wary when motoring.
Last story - i snagged a driftnet line 5nm off the south coast of
nova scotia when a first bought my
Gemini and before my rudder wedges were installed. 4 am, 20 knots of
wind, 4-5 ft seas. Sailing at the time. Basically an immovable object, stopped me dead. Dropped
sails and ended up stern to waves. Had a miserable time freeing port rudder, on a tether, stepping down the stern steps between waves that were cresting up the
deck. Got out of it successfully, but it was not fun to say the least.