The Guardian skill ‘Purging Flames’ was changed into a ground targeted skill with the June 23, 2015 update. The skill isn’t losing its ground targeting aspect when going underwater and makes using it extremely difficult, especially when near the surface of water so deep the ground is out of range. And it’s impossible to use it on enemies that aren’t close to the ground underwater, effectively making it completely useless.
http://wiki.guildwars2.com/wiki/Targeting#Ground_targeting
Most ground-targeted skills which can be used underwater lose that property upon going under water, instead the effect is either applied at caster’s location or targeted foe’s location.
So while underwater it should go off at the player’s location or the enemy target’s location. To be honest I don’t understand why it was even changed to a ground targeted skill in the first place. I liked it the way it worked before the June 23rd patch.
(edited by Charrbeque.8729)