You are able to damage your own vehicle whilst riding it if you are within an End Crystal

Steps to Reproduce:

1) Make a floor out of Obsidian blocks and place one End Crystal

2) Place a boat down next to the End Crystal and ride within it

3) Press F3+B and look within the vehicle's hitbox

4) You are able to break/damage it or press right click on the boat itself

Observed Results:

Hand performs animation when right clicking.
Boat takes damage when left clicking.

Expected Results:

Nothing to happen when right clicking.
End Crystal to blow up when left clicking

Other notes:

This works with any vehicle including: Minecart, Mob (e.g Mule), Boat and is adjustable for the mobs by breaking the Obsidian below the End Crystal and submerging the player's head within the End Crystal. I've included interacting in the title because you can also feed the mob whilst riding it in the End Crystal.