Hi Craig, If you sail anywhere in New England you will have the lobster pot warp problems. The people that suffer the most from the problem are the fin keel / spade rudder folks, where the warp catches on the leading edge of the keel; or hangs up between keel and rudder; ...........and if you haven't protected the area where the rudder meets the hull with some deflector device, you stand an excellent chance of jamming the pot warp between hull and rudder. Then you really have fun trying to get it out............! Prop shafts hanging in the breeze and rotating, are just looking for something to grab; and they are very efficient at doing it........... My old big boat had the classic CCA design with a long keel and the rudder was attached to the end of the keel. The prop ran in an aperture in the rudder and was reasonably well protected. I never had lobsterpot warp problems; and sailed over many of them.......... With a Montgomery, I'm sure you will ride over the pot warp and then have the warp hang up on the leading edge of the rudder. With an M15, just lift the rudder and it's clear. With an M17 you are going to need a long boat hook to do the job. Connie