## Facts

- A collision occurred in the Mobile Bay ship channel in clear weather between the motor vessel *Martha Anne* (a small banana carrier) and the steamship *Ceara* (a larger Norwegian freighter).
- Both vessels were under the control of harbor pilots at the time.
- As the vessels approached each other, the *Martha Anne* suddenly sheered from her course into the *Ceara*’s path, and the vessels collided at close range.
- The owner of the *Martha Anne* claimed the sheer resulted from unavoidable accident or an unknown cause despite reasonable precautions, suggesting possible mechanical failure or hydrodynamic forces.
- The owner of the *Martha Anne* also alleged contributing fault by the *Ceara*, including failure to maintain a proper lookout and negligent engine-room response to bridge orders during the emergency.
- The district court found the *Martha Anne* solely at fault and awarded damages to the *Ceara*’s owner; the *Martha Anne*’s owner appealed.

## Issues

1. Whether a vessel’s sudden sheer into another vessel creates a presumption of negligence, and whether the sheering vessel rebutted that presumption by proving unavoidable accident or inscrutable fault.
2. Whether alleged faults by the non-sheering vessel—particularly absence of a lookout and alleged engine-room errors—constituted causal negligence requiring divided damages.

## Decision

- The Fifth Circuit affirmed the decree holding the *Martha Anne* solely liable.
- The *Martha Anne*’s sheer triggered a presumption of negligent navigation, which was not rebutted by proof of an unavoidable accident or an unascertainable non-negligent cause.
- Even if the *Ceara* violated a lookout requirement, the evidence showed the sheer occurred too late and too close for a lookout to enable effective evasive action, so the omission was not a contributing cause.
- Alleged engine-room mishandling and the *Ceara*’s emergency maneuvers were not shown to have caused or contributed to the collision.

## Legal Principles

- A vessel that unexpectedly sheers into another vessel is presumptively negligent; the burden shifts to the sheering vessel to provide sufficient proof that the sheer occurred without its negligence.
- “Unavoidable accident” or “inscrutable fault” defenses require strong, affirmative evidence that all reasonable precautions were taken and that the accident’s cause was non-negligent or could not be ascertained despite diligent inquiry.
- In collision cases involving statutory or rule-based faults (e.g., failure to post a lookout), liability depends on causation; where the circumstances show the fault could not have contributed to the collision, the vessel is not charged with contributing negligence.

## Conclusion

The court held the *Martha Anne*’s sudden sheer presumptively established negligent navigation, and the owner failed to prove a non-negligent cause or unavoidable accident; the *Ceara*’s asserted shortcomings, including lack of a lookout, were not causally connected to the collision, so damages were not divided.


Atkins v. Lorentzen, 328 F.2d 66 (5th Cir. 1964)