I learned a lesson this last weekend - many of you know this I am sure, but for those who don't... I had sailed back across the "slot" in SF Bay and had two reefs in the main (25+kt winds). Then I turned into the Oakland Estuary on a run and after a while decided to shake out the reefs. Rather than try to center the boom and head up (across a very busy estuary) I decided just to crank up the main in place. It was easy to do since the forces on the luff were not that great. However, when I looked up I saw that the top (full) batten had found its way onto the other side of one of the aft shrouds. Not only that but when I tried to drop the main it jammed between the shroud and the topping lift. Now I had a full main up in a crowded estuary and a fairly strong breeze and no way to get it down. Fortunately with some loosening of the topping lift and some up and down on the halyard combined with pulling down on the luff I was able to get it free. But I can see that it might have been very hard to do. Next time I'll either leave the reefs in or find the room to center the boom and head up. Richard