['16 TT250]

Is it Ok to move another person's boat, or anything else, without their permission?

We were having lunch at a restaurant, my boat was at the public dock. A very nice 60' yacht pulled up to the dock and tied up in a private part of the dock that's clearly labeled "no docking". They had a conversation with the guy who runs the rental boats who has the rights to that part of the dock so I assumed they got permission. Next thing I know a couple guys from that boat start untying mine to move it so they could get out of the 'no parking' end of the dock. My friend & I bolt out of the restaurant and, from a distance, put a stop to that and they re-tied it. We made our way down to my boat and they acted like it's no big deal to move another person's boat. I was pissed, but also thinking that if done safely it really shouldn't matter....but I don't know these people or how they handle a boat. Part of me feels like it's not really an offense, but the rest of me thinks you just don't mess with other people's stuff. It would be like someone moving your bike to make space for theirs. If done without harm it really shouldn't matter, but is it ok to do that with someone else's stuff?

I kept my friend from knocking them all out and I moved my boat to be nice, they helped, then I was left wondering what the general consensus on something like that is.