How do we know the ferry did not signal the Fisher?
Are "we" guessing here?
Tonnage rule always works,i.e. be vigalant when in a commercial traffic area and stay away from commercial vessels. It's worked well for me.
A friend happen to be on the ferry and reported that the ferry made no warning blasts but suddenly went into reverse and the bow dipped way down. Again, the very knowledgeable couple on the ferry heard no warning horns. I heard second hand from someone who talked to a boater who was buddy boating with the Fisher that he and the Fisher were motoring up the channel and the Fisher was overtaken by the ferry and hit from behind. All this agrees with the article referenced above.
From what I've heard and read, I think IB got it exactly right, being big and wrong is still wrong.