The more-maneuverable vessel is supposed to give way to the less-maneuverable vessel, I think. Tankers do not turn on a dime. The destroyer captain was responsible for ensuring that he did not collide with anything. he is toast.
Although there are situations where that is applicable, in general it's not that simple. Here are the rules if you care to peruse them Navigation Rules International-Inland.
The destroyer captain was responsible for ensuring that he did not collide with anything. he is toast.
That statement is correct.