I seem to remember watching a TV programme (Tomorrow's World on BBC, I think) a good few years ago that featured devices in development to prevent helicopters capsizing completely after ditching, but haven't heard anything since.
I had a look on the internet and found the following web site and also found out that the CAA had conducted trials in 2001 into escaping from a side-floating HUET.
http://www.bmtfm.com/devices_to_prev...icopter_to.htm
Anyone heard/know any more? Comments? Opinions?