In admiralty law, collision liability is assessed against the party who was at fault, either by violating a rule of navigation or failing to exercise nautical skills. The error committed by a vessel, however, must be a contributory cause of the collision.

Occasionally, vessels that commit navigational errors are exonerated from collision liability under the "error in extremis" doctrine. The doctrine was introduced in the United States in 1852 and promulgated by the Supreme Court in the Blue Jacket case (144 U.S. 371)

"Where one ship has, by wrong maneuver, placed another ship in a position of extreme danger, that other ship will not be held to blame if she has done something wrong, and has not been maneuvering with perfect skill."

A navigational error presupposes a reasonable opportunity for ships to take corrective measures to avoid collisions. However, the opportunity may not present itself in cases of sudden peril where an innocent vessel is thrown into a dangerous situation by the negligent navigation of another vessel. The extremis doctrine is applied in such cases to rectify this situation.

In admiralty law, judges will not second guess decisions made by competent captains in collision cases. Instead, the court will attempt to place itself in the position of the master at the time of the incident. This is especially true in extremis situations. However, the extremis doctrine does have limits. Incompetence or gross negligence will not be excused. Furthermore, the doctrine is not applicable to a vessel that is to blame for the perilous situation.

In the recent Manhattan Prince case (1990 A.M.C. 1475), the U.S. Court of Appeals for the First Circuit affirmed an earlier federal district court decision absolving a tugboat operator of liability for an accident in which a tanker hit a pier. The case is unique because the error in extremis doctrine was applied to a vessel in peril (the tugboat), even though the vessel was without fault. This is contrary to the fault concept upon which the doctrine is based

The case involved an Allison (collision between a moving vessel and a stationary object) of the tanker Manhattan Prince while docking in Puerto Rico. The 805-foot tanker, with a 124-foot beam and a draft of 32 feet, was carrying 34,800 tons of oil at the time of the Allison. The tanker was manned by a Polish crew that spoke little English and no Spanish. The tanker's compulsory pilot spoke no Polish. He guided the ship to the dock by giving course and speed orders to the master in English who relayed them in Polish to the crew.

The assisting docking tug was secured to the tanker's bow by two lines. Only the pilot could talk to the tug via VHF radio in Spanish and English. The pilot, stationed on the tanker's bridge, could not see the tug. The tanker's bow watch could see the tug but could not communicate with it because of the language barrier and because its radio was on a different frequency. Furthermore, the pilot could not hear the communications between the bow and the captain of the tanker.

When the tanker was 50 feet from the pier, the tug, in order to save itself, cast off its lines. The tanker continued moving forward and struck the pier head on.

The district court found that the Allison occurred because of the tanker's excessive speed and its master's failure to apprise the pilot of the distance between the tanker's bow and the dock during the maneuver. The court also found that the tug's actions did not contribute to the Allison and it had no liability. The case should have ended there, but it did not.

The court went on to hold that the error in extremis doctrine applied to the tug (even though the tug committed no error). By affirming the decision, the circuit court ruling has the potential to extend this reasoning to future cases within the jurisdiction of the First Circuit, which includes the states of Maine, New Hampshire, Massachusetts and Rhode Island, plus Puerto Rico.

It remains to be seen if other courts will follow this novel approach when innocent vessels, that commit no errors, are placed in peril by negligent ships. The words "peril" and "extremis" are not synonymous in admiralty law.