Unable to Place the Island River Boats from the update Podboat Regatta v2.89.0.

Please know that the Boats can be placed above the River tiles. You can first arrange the items in the area. 
Island River Boats: 
Lazy’s Boat
Dreamy’s Boat
Harmony’s Boat
Brainy’s Boat
Vanity’s Boat
Hefty’s Boat
Flowerbell’s Boat
Lazy’s Tunnel 
Inktopus


 
You can see how you can place it in the game. Once you arrange the boats, you can tap and it will start roaming. Only the Flowerbell’s Boat and Inktopus can be placed directly above the river tiles. You can find under Build Menu> Smurfs' tab>Specialty Smurfs' menu>Tiki river tiles.