Here's my submission for The Jungle Cruise:
https://infinity.disney.com/toybox/36756fdb764e4c649518b4f637c8ebd0Nevermind the terrible screenshot. First upload was from the PC version; final upload (before challenge closed) was from the xbox and it looks much nicer/different.
I guess I wasn't the only one to make a rideable raft, but I made mine a collection challenge too. Wasn't sure how closely to the real world ride we should stay, so I didn't! @MightyGitis good call using water textured blocks. The river terrain cubes have a serious collision detection issue which causes the raft to sometimes hang, requiring a little help from the rider to get going.
Didn't get a chance to test across platforms. Let me know how it runs for you.