Beachmaster
In order to establish order out of the chaos of the D-Day beach assaults, United States Navy officers (as part of naval beach battalions) were assigned to specific sectors of each beach and given the title "beachmaster." Outfitted with standard Army equipment, they could be identified by their white armbands, marked with a large "B" and the smaller word "beachmaster," and the Navy markings on their helmets.
The beachmaster's duties included communications between vessels at sea and the troops on the beach, as well as the important task of helping troops, often-times scattered and in the wrong location, to reach their proper objectives. The beachmasters were not only valuable during the initial invasion, but just as important later on in directing the flow of men and equipment that arrived after the Normandy beachheads were secured.
Although no beachmasters are readily visible in Saving Private Ryan, there is an obscure and difficult to hear reference made to them (by what appears to be a 29th Infantry soldier) as Captain Miller is collecting his men and establishing his location. The lack of a beachmaster in Miller's general location may explain some of the confusion shown by some of the soldiers.