I have also had this with end crystals as passengers, but I can't seem to reproduce with those right now.
This bug works with ghast fireballs, blaze fireballs, tridents, primed TNT and lightning bolts carrying the boat (as far as I have tested).

Steps to reproduce:
1. Execute the following command:

/summon trident ~ ~ ~ {Motion:[0.0d,1.0d,0.0d],Passengers:[{id:"boat"}]}

2. The game crashes.