He's unconscious at 5, 0, -67 . You'll be jumped by some Bloodsabers as you approach him.
Find the Bloodsaber Poxreapers in Antonica (3) and Investigate the water supply (3). Both these updates are along the aquaduct on Antonica. You;ll be attacked by the Poxreavers, and click the colored green or white spot near the water spot to investigate the water.
-237, 7, -115 where the aquaduct leaves the ridge.