Complex sentence: The charts were also missing details of underwater obstructions and, as a result, the escorting minesweepers hit several uncharted shoals during the approach, while one of the APAs, "American Legion" also later ran aground on an uncharted shoal.
Split into simpler sentences: The charts were also missing details of underwater obstructions and, as a result, the escorting minesweepers hit several uncharted shoals during the approach. One of the APAs, "American Legion" also later ran aground on an uncharted shoal.