Thanks everyone!
Thanks for all your answers - I now get the general gist of the inflatable floats.
Great photos too Aesir and Heliport. Its obvious now that the floats do block the doors, but then you probably wouldn't be able to open the doors with the water pressure outside - hense the windows which pushout.
Lu - I like the last photo on that site you posted of the two people sitting on the top of the heli. I wonder if they were able to start it back up and fly home!!?
I'm quite impressed by the photo of G-TIGK - it's floating pretty high up in the water in rough seas and thats a big heavy heli too!
Thanks again,
G-ANDY