Threw a boat

By definition a "boat" is a term to describe a maritime vessel to transport cargo and people. In the stock world when you "throw a boat" at a trade you are in essence placing a stock trade in the magnitude of a normal persons yearly salary. To describe the magnitude of a trade, a person could name a type of boat to indicate the actual size of a trade.

Hey (insert name here) how many options contracts did you buy? I threw a boat at it
Hey (insert name here) how many options contracts did you buy? I threw an aircraft carrier at it
Hey (insert name here) how many options contracts did you buy? I threw a fleet at it