Realistically I’d guess the minimum righting weight for the F16 would be somewhere around 190 lbs (87kg.) the Taipan would require slightly less and the Nacra 17 would require more (weight). <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />
No, The F16 does not require anywhere near that much.
I am about 80kg and I've been told I'll have no problems with mine, and I believe there are even lighter sailors out there who do not have a problem righting their boats.