Walterd, I don't know the exact mast length but from waterline its supposed to be 46'5". Assume that the mast is a bit longer as the mast step is lower than the waterline. I suggest that you join C&C photoalbum site and post question on their email list, many members with lots of info. As a 30 Mk II owner I am curious as to what happened to your original Offshore Spars mast?
1988 30 Mk II # 90