Have you ever considered hydration on your back? I've never dropped a bottle, but when I'm really working hard I don't really want to change my position. The last race I did I started thinking about one of those camelback jerseys with room for a hydration bladder. Have to admit I'm still out on this one because... it looks so ugly...

Just a suggestion, but I guess 10 days before a race is not a good time to try out something new.