When I was in Greece, I wore a rash guard one day and I got some chaffing on my jaw line from the shoulder of the shirt. I think it's the same sort of thing.
Your head might FEEL like it's down, but it should be neutral. If you're head is too high, it'll feel low, though. So, you don't want your chin touching your chest, you want it in a neutral position, only horizontal instead of standing up. Make sense?
When I had my chaffing, I put vaseline on my jaw while in the water....body glide would likely work better for you, though. I'd put it on your shoulder, not in the beard. Also, make sure that you don't have stubble where there's not supposed to be stubble.
Ferries are for wimps!!
Swim Trek '08