Thanks a lot for the replies

The water is the main culprit for the long render time. Its about 10 hours down to the water, and im guessing about 40 for the water. I will give the masking of the water a go when i get my computer back, in about a week. Also, i havnt had much experience with GI, but do you think i should have GI surface details unchecked for this render? Thanks again.