Yes, there's a cutlass bearing in each prop strut, including the last one right at the prop. If the line was all aft of that, I can't imagine how the line hurt anything unless it kept water from exiting the last bearing.
Many marinas can handle this type of issue. Likely people here can tell you whom in Miami area does good running gear alignment work, or if not, just look up a few, call around and pick one.
If the answer to the question about if you saw the vibration at the engine end of the shaft is yes, first try taping a pointed stick to a strut on the engine room floor with the point 1/4 inch away from the shaft. Then have somebody else run the boat at idle while you watch the shaft vs. the end of the stick. If the shaft wobbles, you'll see it easily. Then try the same thing at 1200 RPM, because running gear kind of self aligns when working. Again, note if there's much wobble evident at the shaft. You may find that it's the packing gland that wobbles, which they sometimes do, and the shaft itself is running true. If the shaft wobbles, then show that to the marina you select. They'll send somebody out with you to see what you saw so they can evaluate it. They do have special equipment, but usually somebody that knows what they're doing can do the primary cause evaluation by hand and eye.
If it's something like an engine mount that gave out, maybe they can do it in the water. If it's a wobbling gland, maybe the weekend fishing trip can still happen. If it's shafts - props - bearings, they'll haul it and it usually becomes apparent upon inspection by a knowledgable person and can be fixed there at the marina. If it's very minor, maybe they'll tell you not to worry about it unless it gets worse. If it really is significant shaft vibration, you need to get it fixed right away.
My 53MY had vibration when I bought it. When it was hauled, I taped a pointed stick to the rudders with the point exactly at the center hole in the end of each prop shaft, about 1/4 inch away. When I turned the props by hand, the sb shaft showed wobble compared to the stick. I got a marina tech and he verified it and did the work. That shaft couldn't be straightened so I spent $800 for a new stub shaft and also got new cutlass bearings on both shafts and alignment of both shafts. Now it doesn't vibrate (until I hit the next thing or run shallow
).
Stuff happens, and you get it fixed. It's good that you noticed it.
Good luck and let us know how it goes,
Doug Shuman
