The U.S. Navy is applying its Sea Swap program to its twelve amphibious task forces (or expeditionary strike groups in navyspeak). This will allow four of the task forces to be disbanded. That means the older ships would be retired, leaving the eight remaining task forces with the most modern ships and equipment. The money saved would allow the navy to buy more pre-positioning ships. These large civilian type transport ships hold the equipment for marine brigades, and allows a combat ready marine brigade to be put on the ground quickly once the troops are flown in to man the equipment that was stored at a local anchorage. The Sea Swap program keeps the ships out at sea longer (usually at least 18 months, versus the traditional six) and simply swaps the sailors and marines every six months by flying replacements in, and the returning personnel back to the United States. This saves the ships weeks of movement to their overseas stations every six months. A new class of larger pre-positioning ships would have smaller craft that could move vehicles and equipment from ship to shore, for those cases where there is no port available for the ships to dock. Pre-positioning ships are Ro-Ro (Roll On-Roll Off), which means they are designed to allow the vehicles to just drive off onto a dock and into action.