Called a “heavy –lift ship”, this vessel is able to lift and transport other ships from the water or move oil rigs across the sea.
SBX-1 - The Sea-Based X-Band Radar, which is a floating, self-propelled, mobile active electronically scanned array radar station designed to operate in high winds and heavy seas. It is part of the U.S. Defense Department Ballistic Missile Defense System.
Drilling rigs with a gridwork of iron below them creating a giant footprint to stabilize the weight. They jack up out of the water with those large legs.