just noticed this topic..
i.m.o look for the flattest water available to initiate the gybe on, nothing flatters a gybe like flat water...the real test is initiating and maintaining speed through a gybe in chop! and i dont think i have seen anyone do it as well as slow boat..he would be the best to comment on this.
he gave me some tips a couple of weeks ago for gybing in chop and the 1 thing that really stuck out was his comment about maintaing mast foot pressure via pulling down on the front hand through the turn as much as possible.
for us light guys it can be hard to gybe in chop because you cant get enough weight on the rail as you bare off and try to set the leeward rail its easy to start bouncing over the chop which then leads to problems.
leaning forward in the turn,pulling down on the front hand (which should be fingers over the boom) even sliding the mast step forward a little will help keep the board carving through the chop.
as i said gybing in flat water is very easy as you dont have the chop pushing you about and off balance, gybing in chop fast is what sorts the men out from the boys and unfortunately i am still a boy at that

here is link to a flat water gybe.
www.seabreeze.com.au/gallery/gallery.asp?imageid=8822