Completing the Collect Water From The Swamps quest

[Dark Sceptor]

I'm did the swamp trip in the savanah by way of the cave paintings. I entered the swamps and now need to collect water from the swamp. However there are no markers on the map as to where I need to go in order to get the needed Action point. Any suggestions?

[Pinger]

move to the water in the marshy area and first sample should be possible, there should be a use action looking at the water, then move about 200m east along the marsh until you can use the water again /repeat

[Nightwalker]

There are three spots in a row. Looking down into the area from the outpost above it I first search in the quadrant to my left. Once I find that spot the next two are almost directly to the right (as I'm facing towards the river, of where I find the first one. 100-200 meters separate each place.