if you push the trolley through the rails into the boat, they connect, then you can put a pig there, after putting a saddle on the pig and sit on the pig and drive into the water block, you will be thrown out with the pig, after which you can walk, kill through walls,watch from 3rd person, build near the pig, if you go too far you can see the end of the chunk loading, after if you press the shift you will be teleported to the pig.

links on video:

https://youtu.be/BNiDtGsAOc0
https://youtu.be/7g4al1qpv1o
https://youtu.be/afP9RXbCm4k