This must be some type of joke.
You would probably get more insight on the ranger forums but my guess is his pet kept reviving him
Grenades do jack squat underwater unless the target is 1) not moving and 2) against solid surface.
If the target is moving away from you (or even perpendicular), the grenades will miss. If the target is not against a surface, 1-2 of the grenades will go right past them doing nothing.
To conclude, do not use grenades underwater.
Only time im using Nades, is when hes stopped and im right on top of him.
Should of got it on fraps
The underwater pet resurrect is just ridiculous – I’m fairly certain it’ll be fixed.
I had the same problem about a week ago, I finally manage to finish him off with a well timed speargun burst , he actually survived longer in downed state than alive (I even used elixir x to try and finish him).
engie roaming vids: http://www.youtube.com/channel/UC9NnXVfY4vRU1F-X7b1Oorw/videos