So, from what I understand, all entities are able to ride in boats as passengers, right? So, since Minecarts are entities, doesn't that mean they should be able to as well? Every time I try to put a Minecart, (or, more specifically, a Minecart with Chest), in a Boat, the Minecart just sinks to the bottom of the body of water and doesn't get in the Boat. Is that an intended behavior, or a bug? Here's what I did:
1. Place boat in water at shore.
2. Place down a small Minecart Track leading to the Boat.
3. Place a Minecart with Chest on the track.
4. Push the Minecart with Chest down the track to the Boat.
5. Push the Minecart with Chest off the track at the Boat.
6. Watch the Minecart sink to the bottom of the body of water and not board the Boat.
7. Repeat until you give up in frustration and write this bug report.
Hope this helps, or, at least, hope to get an answer as to how to get a Minecart with Chest in a Boat.
P.S. I can still technically do it, but I have to use commands, so it's not really that useful, since that will lead to a world overrun by Boats and Minecarts with Chests. Rockatoa, Brickticks out!