Take off performance is predicated on no ships in the channel. If there is a ship, it is like a big TV antenna or mountain is temporarily parked off the end of the runway.
That obstruction invalidates your t/o perf data. If do not have takeoff data that covers existing conditions, you cannot go.
What amazes me the most is the comment "Sludge" made about the captain being a Jerk and impying that for economic reasons they should take off anyway.
It would be unsafe and illegal to take off with the ship in the channel while the Performance data is based on no ship.
This is SOP at KBOS. As a Captain, you wait and coordinate with all of the involved parties to get the performance data you need.
(BTW, I learned many years ago not to try and fly another man's airplane. It is impossible if you are in an airplane nearby, much less at a keyboard thousands of miles away, getting third-hand information from a web-board)
R