Editing PT boat (section)

===Barge attacks===
Perhaps the most effective use of PTs was as "barge busters." Since both the Japanese in the New Guinea area and the Germans in the Mediterranean had lost numerous resupply vessels to Allied air power during daylight hours, each attempted to resupply their troop concentrations by using shallow draft barges at night in very shallow waters. The shallow depth meant Allied destroyers were unable to follow them, and the barges could be protected by an umbrella of shore batteries.

The efficacy of the PT boats at sinking the Japanese supply barges was considered a key reason that the Japanese had severe food, ammunition, and replacement problems during the [[New Guinea campaign|New Guinea]] and Solomon Island campaigns, and made the PT boats prime targets for enemy aircraft. The use of PT boat torpedoes was ineffective against these sometimes heavily armed barges, since the minimum depth setting of the torpedo was about 10 feet (3 m) and the barges drew only 5 feet (1.5 m).<ref>{{Cite report |url=https://archive.org/details/navalordnanceandgunnerynavpers161161944 |title=Naval Ordnance and Gunnery |date=1944 |publisher=U.S. Government Printing Office |pages=212–213 |id=NAVPERS 16116-A |place=Washington, D. C.}}</ref> To accomplish the task, PTs in the Mediterranean and the Pacific (and [[Royal Navy]] and [[Royal Canadian Navy]] motor torpedo boats in the Mediterranean) installed more and heavier guns which were able to sink the barges.

Although their primary mission continued to be attack on surface ships and craft, PT boats were also used effectively to lay mines and smoke screens, coordinate in [[air-sea rescue]] operations, rescue shipwreck survivors, destroy Japanese [[Japanese Special Attack Units|suicide boats]], destroy floating mines, and carry out intelligence or raider operations.