Tire choice for wet grass
So I'm a total cross newbie but after having done a couple I have come to realize that I can hold my own most everywhere except really really wet grass. Most of the cross races around here are held in parks on grass and when I come upon the really wet sections with borderline standing water on the grass I sink like stone and it feels like I'm riding through quick sand barely able to maintain forward momentum while other people seem to just float over the stuff and ride away. Now is this a bike set up issue? Is there some secret to this type of terrain or a tire that works well in it or am I just a nancy boy who needs to pedal harder and quit whining? I am a fairly heavy guy (about 200 lbs) which I don't think helps matters and I run Michelin Mud2's at around 40-50lbs.