Complex sentence: The direction of the landing operations were trusted to Col. Emilio Sotomayor, brother of War Minister Sotomayor, while Thompson was in command of the naval stage of the disembarkment, directing the landing wave boats.
Split into simpler sentences: The direction of the landing operations were trusted to Col. Emilio Sotomayor, brother of War Minister Sotomayor. Commander Thompson was in command of the naval stage of the disembarkment and directing the landing wave boats.