I found underwater diving in Sims 3 kind of boring, diving to me was just a reskinned collection, except instead of searching for things on land you did it underwater, and it was deadlier. I will say though I am dissapointed by the fact that we don't have any under water lot types what so ever, I would've loved to build an underwater groto for my mermaids to live in/chill.
Bottom line, I'm not dissapointed by the absence of real diving, they seemed to subsitute the diving with enough other game play that makes more sense for what the pack is called, "Island Living," and by the looks of it, living on Sulani is quite a different experience than living in the other worlds on offer in Sims 4.
