i see it robbie and aye we do wait for the blue or sun if its in the mood, no birds leave unless there is orientation by blue or sun, high cloud n bright n good vis for 2 mile normally ok but only with old birds,convoy over say 600 usually leave in a batch but 1000 or over allways split into batches , i think its a natural thing for to combat predation, the way it is now ime afraid, y/b you need broken blue with sun if poss but in early races you might get a percent of the convoy who never seen a race crate so on lib can really ef up birds trying to get a line, this is the thing everyone should be in with y/b frome the start nae 2 wks later, race prog at fault there,omo of course.