Once upon a time one could, with a Puma or Super Puma, take off with offshore diversion so that if you lost an engine you would, quite safely, land offshore with one engine. Helicopter Services also did it with S61s in the 70s but after a couple of training accidents the practice was banned in Norway.
The UK oil companies cried off in the early eighties so everybody carries onshore diversion fuel. For a simple engine failure the land option is always used unless there are signs of something else going wrong; collateral damage, dirty fuel etc.