The German and Italian evacuation schemes proved highly successful. The Allies were not able to prevent the orderly withdrawal nor effectively interfere with transports across the Strait of Messina. The narrow straits were protected by 120 heavy and 112 light anti-aircraft guns. The resulting overlapping gunfire from both sides of the strait was described by Allied pilots as worse than the Ruhr, making daylight air attacks highly hazardous and generally unsuccessful. Night attacks were less hazardous and there were times when air attack was able to delay and even suspend traffic across the straits but when daylight returned, the Axis were able to clear the backlog from the previous night. Nor was naval interdiction any more practicable. The straits varied from wide and were covered by artillery up to in caliber. This, combined with the hazards of a current and fear that Italian warships were preparing to attack the Straits of Messina in a suicide run, made risking warships unjustifiable.