I don't believe this is a bug. It's considered a vehicle (like a horse or mine cart) but has no health, which would replace the hunger bar. On top of that, you don't lose hunger in a boat so it's not a problem.
Instead, maybe Mojang should implement a hunger bar into vehicle GUI so that people aren't blind if they take damage when in a vehicle.
I don't believe this is a bug. It's considered a vehicle (like a horse or mine cart) but has no health, which would replace the hunger bar. On top of that, you don't lose hunger in a boat so it's not a problem.
Instead, maybe Mojang should implement a hunger bar into vehicle GUI so that people aren't blind if they take damage when in a vehicle.