Mid 80's flying a Puma over the jungles of Belize. Hell of a bang from the back end and a tad of vibration set in (this 'tad' was strong enough that I couldn't read the instruments and the scene outside was just a blur). decided it might be prudent to land but, dark green everywhere I looked apart from a lighter green blob. Decided to land there. Crewman pushed out a Mayday on all freqs (he decided to become a pilot after this incident). Made an approach to the green blob - turned out to be a swamp with 10ft reeds. no choice, so shut down. Aircraft settled into the swamp and rolled about 10degrees. Sigh of relief. Bigger sigh when I looked at the tail rotor to see the pockets on one blade had all departed. Not impressed by the crack all the way down one side of the tail boom just in front of the intermediate box. Engineers subsequently reckoned that another 45secs of flight and the whole tail assembly would have come off. Battle damage repaired and flew it out 10 days later. What really made me think was that the day before I had been 100mls out to sea, with no comms with anyone , flying the same aircraft. Hey ho!