Jose Castillo’s life-altering incident happened June 8 on Pier 40 at 353 West St., where he was working as a line catcher, handling the ropes used to moor vessels, according to the lawsuit, filed this week in Manhattan Supreme Court.

Castillo claims in the suit a captain’s negligence caused him to lose the middle finger on his right hand.

As he was loosening the lines on the departing Freedom Boat, “the captain . . . suddenly, and without any warning, negligently and recklessly sped away from the dock while [he] was still holding the ropes,” the suit claims.

Castillo’s finger became wrapped in the ropes.

“The skin of [Castillo’s] right hand middle finger was completely detached from the bone as a result of this incident,” he continued in court papers. He “was immediately transported by ambulance to Bellevue Hospital,” where doctors had to amputate the digit.

The lawsuit, which also names Freedom Boat owner New York Water Tours, alleges Castillo “will never again be able to work as a line catcher, or any other comparable maritime position.”

Neither the tour company nor their lawyer returned requests for comment.