Underway replenishments, universally known as UNREPS, are uniquely Navy and one of the most dangerous evolutions ships go through on deployment and when underway for extended periods of time. Thousands of tons of steel cruise through the pitching ocean about 150 feet apart as they transfer fuel, ammunition, spare parts and food to ships on the pointy end of the spear. They often take several hours to complete.
This is a video of two destroyers (ROOSEVELT (DDG 80) and MASON (DDG 87) according to the clip) conducting simultaneous UNREPS with USNS LARAMIE (T-AO 203) in the FIFTH Fleet AOR (Middle East).
(Sorry…I couldn’t help myself.)
Thanks to time lapse photography and a GoPro camera, you can see the whole thing in about four minutes.
[Note – UNREPS are known more officially as Replenishments At Sea, or RAS]