Neither the corporation, nor any officer or responsible employee in the corporation in charge of canal structures or forces thereof, or other public officer employed upon or in charge of the canal system or part thereof shall be liable to arrest or to be held to bail in any civil action for any act done or omitted to be done by it in the exercise of its official duties, nor be subject to military duty while actually engaged in their respective employments upon the canal system while the same is navigable.
New York Legal Code