The technology will allow wind power to be harvested in waters that are too deep for the existing bottom-standing turbines.
The wind farm, known as Hywind, is a trial project which will bring power to 20,000 homes. The output from the turbines is expected to surpass generation from current ones, according to the Norway-based manufacturer Statoil.
"This is a tech development project to ensure it's working in open sea conditions. It's a game-changer for floating wind power and we are sure it will help bring costs down," said Leif Delp, project director for Hywind.
The huge turbines are currently being moved into place.One giant turbine has already placed, while four more wait in a Norwegian fjord.
By the end of the month all the turbines will be towed to 25 kilometres off the shore.
The turbines can operate in water up to a kilometre deep.
Each blade is 75 metres long - almost the wing span of an Airbus, the manufacturers said.
The blades harness breakthrough software - which holds the tower upright by twisting the blades to dampen motions from wind, waves and currents.
The operation to begin shifting the first of the 11,500 tonne giants involved the crew securing thick cables to tug boats and using remote-controlled submarines to check for obstacles.
Floating on a sealed vase-like tube 78 metres deep, the turbine's bottom filled with iron ore to weight the base and keep it upright in the water.