@ingridmf First off even if you absolutely refuse to mess with a IP fix you can do every single little thing from that aside from finding a hidden island and deep diving wherever there is water.So if you have Sunlit Tides even Sunset Valley you can boat there,paddleboat there jet ski there,windsurf there and snorkel there.You can start a Hotel there and raise it from a single star junk hole to a 5 star resort etc etc.
You can even live on an island in SV
An example these really are simple
https://i.imgur.com/aCVJZcR.png
This I just made in SV a few days ago
https://i.imgur.com/dLt3Z5G.png
Can lay on beach towels and put up umbrella and read everywhere
Build sandcastles play in the sand
Can be a mermaid even in SV
Pool bars can be used any pool even your house
Pool slides used anywhere you want
All in one bathrooms are just a must a one square sized shower toilet opens up soooo many tiny living home options.
Plus IP has great clothes and hair and the spawners also can be used anywhere so if you want to check SVs beaches for seashells to collect you can.
I see why others say SN and it is great but you seem to say you prefer realism.