Guild Wars 2

Several people are already aware of this bug and exploiting it. When you reach the surface in a downed state underwater, you are supposed to not be able to move while on the surface. However, when you take damage, you can swim down underwater and back to the surface. During this time, your character is completely immune to all sources of damage. This essentially makes players invulnerable.

Maybe that’s why it’s so impossible to kill anyone when they’re drowning. :S I really would like to see an option to finish players in this state. It’s like a full second HP bar to deal with.

Yep, it takes ~ 5min to PK someone when they are exploiting this bug. Very annoying.