Again, depends on the job,
If it's a vessel with gear failure and no life is in danger, then they should adhere to the limits.
Similar to the police, if the blue light ain't on, then they can't get away with burning off the speed restrictions.
We rely on common sense, have only once burnt up a restricted waterway but that was for people in harms way. We were 100% sure this was the case because the CG had given us all the details and told us to make best speed.
A boat is not truly yours until you start fixing the things that you have personally broken.