The LCU 1646 transports wheeled and tracked equipment and general cargo from ship to shore, shore to shore, and in retrograde operations. Although the Navy now has a newer craft, the Landing Craft Air Cushion (LCAC), the LCUs have the backbone for heavier loads. Its development and design updated the landing craft used in World War II, made famous by the invasion of Normandy Beach. However, it requires a 9 foot draft beneath it's keel to operate safely, making it less versatile than the LCAC, which flies on top of water or ground. Another difference between the two landing craft is the LCU is home away from home for its crew, because it can operate independent of the amphibious ships on which it embarks. It contains living compartments that include sleeping quarters, a wash room with shower, a clothes washer and dryer, a lounge and a complete galley, making them able to operate at sea for up to 10 days. LCUs have both bow and stern ramps for onload/offload.