Excerpt from Carlo D'Este, Fatal Decision, P-486, Note #4 (the beachhead commandos):
What few have known is that a great debt was owed to the men who had taken great risks to reconnoiter the beaches at Anzio. Some of the most dangerous operations of the war were carried out by what were known as Combined Operations Pilotage Parties, or COPPs. The acronym COPP was used to disguise their real and more descriptive title of Beach Reconnaisance and Assault Pilotage Parties—whose task, in the case of Shingle, was to lay the groundwork for the Anzio landings.
Operating at night in collapsible canvas canoes called "folbots," two-man teams were launched from submarines, and while one would remain several hundred yards offshore, the other would swim ashore to reconnoiter enemy defenses and record important details such as the gradients and composition of the beaches. Often it was either impossible to locate the submarine again or the fragile folbots capsized in rough seas. In December 1943, during the preparations for Shingle, at least two two-man teams were lost off Anzio. Prior to the Sicily landings the COPPs suffered grievous losses to more than half the operational teams in the Mediterranean. In one instance it was believed that the two officers, whose boat probably capsized, deliberately swam out to sea where they were lost without a trace. Both men sacrificed their lives in order to preserve the security of Husky.
During the Shingle landings a folbot manned by a U.S. Navy ensign marked Yellow Beach for Darby's Ranger force and, at zero hour minus 10 minutes, turned on a yellow battle lamp that guided the Rangers to their target.
Disbanded after the war, the COPPs and their secret remained virtually unknown until 1954, when several veterans wrote about them. Only then did the world learn of their unheralded work.
—Peanuts