You did right. I had to dock at the town docks in Alton bay on saturday, all the docks were busy with fisherman/woman, no place to pull in, I idled for a few moments(couple minutes most) until one yelled out at me, "do you need to dock?" I said yes, he pulled his stuff in and I gave him a big thank you. He continued to fish there, when I was leaving he pulled in his stuff and let me on my way. I would have done the same if I was in his shoes. Common Courtesy rules. I think he lost less than 5 minutes of fishing by being courtieous.
I think you have an implied right of way, if it were only a couple of guys I never stop at the bridge at Squam, they pull the lines out as soon as they see a boat coming and when they go by they put em right back in. I don't even ask, I just put my way through.
But if they are shoulder to shoulder I'm sure they are reluctant to move (might loose their place) but that thier problem with the other people on the bridge, not yours.