John Jefferies tracked the hovercraft down to Whitegate, on the east side of the harbour. John says: "It was laid up on the foreshore and while I was taking photos the owner came out and we had a chat. Apparently he imported it from Russia and has a Department of Marine licence to operate it as a passenger ferry. It is a Mars 700 model made in Novgorod. I checked it out and it's Russian owners have a website with photos including one of the craft gliding along the frozen Volga!
The owner's name is Martin and he runs three scheduled tours of the harbour a day, calling at East Beach in Cobh. He also has it on hire for parties of up to 7 people with tours to Crosshaven and to East Ferry and around Whitegate Bay. He's setting up a website at though it's not online yet.
I attach one photo of it at Whitegate, though I didn't get to see it in the water.