If you launch up high when riding a boat (+300 Y) and try to go to 3rd person, it will crash the game.
A way to do it is to place a boat on a slime block, wait a little time, and then ride the boat. After something like +300 Y coordinates when you try to F5, you will crash.
If you are already in 3rd person when doing this, you can see that the player model and the boat will start flickering, eventually disappearing, and crashing.