According to the NTSB, the pilots of the 19-barge Big D tow and the 42-barge Carol McManus tow had agreed to a port-to-port passing arrangement over their VHF radios. This agreement was made approximately 20 minutes prior to their meeting. However, the pilot of the Carol McManus incorrectly recalled the arrangement and also directed his upbound tow towards the same right descending bank.
The report suggests that the pilot of the Carol McManus might have been more likely to remember the correct maneuver if he had repeated the agreement back.
“When one mariner proposes an arrangement to another, the other mariner should repeat back the proposed passing arrangement to ensure both parties have a shared understanding of the arrangement,”