Creepers only deal half a heart of damage to nearby entities when exploding inside of boats

Confirmed in 1.16.1 and 20w27a.

Can confirm in 20w48a. I've attached a command so you can reproduce this issue quickly.

/summon boat ~ ~ ~ {Passengers:[{id:creeper}]}

Can confirm in 21w03a.

Can confirm in 21w05b.

Can confirm in 21w06a.

Video attached.

Can confirm in 21w07a.

Can confirm in 21w11a.

Can confirm in 21w16a. You can use the following commands to easily reproduce this issue:

/summon minecraft:boat ~ ~ ~ {Passengers:[{id:"creeper"}]}
/summon minecraft:boat ~ ~ ~ {Passengers:[{id:"creeper",powered:1b}]}

Can confirm in 1.17.

Can confirm in 1.17.1.

Can confirm this behavior in 21w40a. Here are some extra details regarding this problem.

The Bug:

Creepers only deal half a heart of damage to nearby entities when exploding inside of boats.

Please note that altering the "ExplosionRadius" of the creeper will not increase the damage that you receive.

Steps to Reproduce:

• Summon a creeper that's inside of a boat.

/summon minecraft:boat ~ ~ ~ {Passengers:[{id:"minecraft:creeper"}]}

• Switch into survival mode and approach the creeper.

• Wait for it to explode and when it does, take note of how much damage you took.

Observed Behavior:

Creepers only deal half a heart of damage to nearby entities when exploding inside of boats.

Expected Behavior:

Creepers would deal the appropriate amount of damage to nearby entities when exploding inside of boats.

Can confirm in 21w41a.

Can confirm in 21w42a. I'd like to request ownership of this ticket since the current reporter has been inactive since August of 2018.