How landing-craft flotillas were organized

How were landing craft grouped, crewed, and commanded?

They were organized in task-sized flotillas, with crew numbers and officer seniority rising with craft size and the formation to be landed.

Small LCM groups might place several craft and their tiny crews under one officer, while larger craft carried crews of roughly thirty and warranted lieutenant or lieutenant-commander leadership. Groups could be nested into larger flotillas, but there was no universal number. Organization followed the military load: planners calculated how many craft were needed to move a company or other formation and built the grouping around that requirement. An explicitly unverified story about the beachmaster organization at Gold Beach describes a full captain taking a small craft so he could move around the landing area and solve problems directly. Midshipmen, sub-lieutenants, and even leading seamen could command individual craft, so rank varied with craft size and task.