I've never been to the resort Rose Hall, but I have been to the ruins of the Rose Hall Great House, before they fixed it up and made a superresort out of it. It's actually a couple of miles south of downtown Mobay, close by the very very expensive and exclusive Tryall Golf operation. Lovely ironstone fringed (ouch) beaches, beautiful views, almost at the highest end of high price for Jamaica. The Rose Hall property was fixed up in recent years, and is supposed to be fairly consistent with its Tryall neighbor in terms of luxury,etc. I have never dived in the Tryall area, but there are plenty of dive operations nearby. The Half Moon Resort, just up the road toward Mobay has one, and I'm pretty sure all the local high end hotels will happily arrange diving. I can't comment on the diving, but it's probably ok, unless you are a seasoned dive traveller, in which case you may be bored. Beware the White Witch. A nice art gallery nearby.