This was my entry to the Eurobricks TSATS (To Sail a Technic Sea) competition. It is an oil-rig platform that combines a number of remotely-controlled functions with a unique shape and a good-looking minfig crew.
Its body is an octagon - one of the hardest thing to build an entire platform on. It rests on four air-cushioned legs that can also lift (pneumatics) to raise the entire platform up. The legs can also be rotated in formation (shown in video) to give the oil rig additional rocking-stability in a particular direction - for incoming waves!
The drill arm is fully-operational. It can be lowered its full length and there is a motorized drill head at the bottom.