MIL-C-15730L, MILITARY SPECIFICATION: COOLERS, FLUID, NAVAL SHIPBOARD: LUBRICATING OIL, HYDRAULIC OIL, AND FRESH WATER (23 MAR 1990)., This specification covers lubricating oil, hydraulic oil, and fresh water coolers for Naval shipboard applications for which standards of resistance to shock and standards of construction are higher than for usual commercial marine use.