I'm fine with Island Paradise for TS4 but with more in depth merfolk and less bugs/tech issues.
I don't even care if maps with swimmable oceans are restricted to the pack/areas you create with it.
Mermaids would also give a bit of love to Occult sim fans who have been left to slowly die of thirst in the desert for quite some time.
Out of all the surveys I've seen Summer Holidays is the only one that caught my interest. Underwater/ocean swimming and diving would be wonderful additions to TS4 and they are features that can't really be implemented through mods.
