Since the Vietnam War and the 1967 USS Forrestal fire , United States Navy and United States Marine Corps GP bombs are distinguished by a thick ablative fire-retardant coating , which is designed to delay any potential accidental explosion in the event of a shipboard fire . Land-based air forces typically do not use such coatings , largely because they add some 30 lb ( 14 kg ) to the weight of the complete weapon . Fire is less a danger in a land-based facility , where the personnel can be evacuated with relative ease , and the building be the only loss . At sea , the crew and munitions share a facility ( the ship ) , and thus are in much more danger of fire reaching munitions ( which tend to be more closely packed , due to space limitations ) . Also , losing a munitions storage building on land is far cheaper than sacrificing an entire naval vessel , even if one could easily evacuate the crew
1967 USS Forrestal fire
1967 USS Forrestal fire
General-purpose bomb