Using Lagoon 440 boom as a crane

[coldar1]

Has anyone had experience with using an extension to the boom to lift something on and off a platform above the davits at the stern of a Lagoon 440? I have an object that will weigh in the order of 220kg but will need to be swung out to either the Port or Starboard side to be lowered in to the water. It only needs to be raised about 300mm to clear it's cradle, and slewing the boom may require disconnecting the traveller briefly to get sufficient slew. Any comments please?
coldar1