[tecdave]

Alun's system was very effective in getting the diver to the surface but was a pain to lift the weight to reset it.(hopefully it doesn't need to be reset!) we used a 2m metal bar with 2 large buoys on the end, 2 pulleys on the end of the bar and a sailing rope clutch set on the middle of the bar. The rope ran through the pulleys and the rope clutch and the weight was held to the buoy with a quick release shackle. if it needed to be deployed, you opened the clutch and pulled the shackle toggle. this sent the 20kg down 2m away from the diver coming up. The pulleys reduced friction and increased speed you then use the clutch to stop the rope when the diver nears the surface. Hope you can follow this!!!!!

I will try and dig a pic of it out and post later.

Dave