Guns for naval use were supplied with air from shipboard compressors. Aircraft facility is expanded to accommodate two shipboard helicopters. This is reportedly the first use of shipboard guns in naval history. The first pilots had no signaling system for assistance from shipboard personnel. The results were that aircraft-borne gunfire spotters were significantly more accurate than shipboard spotters. Living arrangements vary by cruise line, but mostly by shipboard position. It also noted weaknesses in situational awareness, maintenance, shipboard operations and transport capability. This class introduced the capability of shipboard helicopter operations. The Navy also has several hundred land-based aircraft that are "not" capable of shipboard operations. High-level maneuvering drones were virtually immune to shipboard AA systems. Many such facilities have areas decorated like shipboard quarterdecks. This allows the holder to adjust, maintain, and repair shipboard radar equipment. The ULQ-6 deception transmitter was one of the earlier shipboard ECM installations. The Navy continues to work to develop a new shipboard working uniform. During the late Goryeo Dynasty, Goryeo was at the cutting edge of shipboard artillery.