She was to have been part of the ill-fated convoy SC 7, but suffered engine trouble shortly after leaving port and turned back.

The extension of German U-boat activities into American waters at this stage in the war as part of Operation Drumbeat (also known as the Second Happy Time) meant that Winona continued to sail in convoys.

She was part of convoy TRIN-19 in October 1942, and was sailing from Norfolk, Virginia bound for Rio de Janeiro via Port of Spain, Trinidad.

The master secured the important confidential documents, stopped the engines and attempted to evade the other ships in the convoy.

The crew remained on board, and after damage control measures stopped the flooding, were able to bring the Winona into Port of Spain the following day.