IronboatLee on officials has found a way to move and place Diving Spots in other worlds. Where there’s a will, there’s a way simmers! The steps to follow are very easy, and just to confirm that it works, I went ahead and tested it out myself.
1) Enter Edit Town Mode
2) Open the cheat box (CTRL + SHIFT + C)
3) Testingcheatsenabled true
5) EnableLotLocking true
6) Select Diving Spot and save it to the Bin
7) Open a new game via the Main Menu
8) Edit Town
9) Place an empty lot into the water (World Editor)
10) Set the lot type to Community > Diving Lot
11) Lock the lot in its current state
12) Save and quit to the main menu
13) Go back into your game and vuala!