In Nancy Drew: Sea of Darkness, Nancy finds a journal with a crossword/word find puzzle inside. The words you need to highlight are all ship terms. These terms are in reference to the ship labeling puzzle in the museum. To create words in rows (left-to-right), use your left-mouse button to highlight the letters in pink.
To create words in columns (up and down), use your right-mouse button to highlight the letters in blue. Follow the guide in the video to know which letters to use horizontally and vertically.
You’ll know you have solved it when all the terms are faded in the list.