Leaving the Dasa Mountain Pass behind you, you arrive in Serpent Canyon: a winding river canyon that leads you away from the Dasa mountains and closer to your ultimate goal - the Skaarj mothership.
You start in the corridor just back from the room with the water feature you saw at the end of the previous map. There's nothing to do here, so climb one of the two flights of steps on either side and go through the door at the back of the room. You emerge in a dock at the back of a cave. Here a boat is tied to a vertical pole on a wooden jetty at the end of a river leading out of the cave. Climb aboard and shoot the retaining rope to get the boat to move. Ride it out into the first stretch of canyon.
The first stretch curves round alongside a small stretch of land to an opening in the rock. Watch out for a Fly roaming in the first section. Beyond the opening, you enter the second stretch, which is similar, with Nali Rabbits hopping around on the grass at the side. Soon the boat floats through into a cave, around whose curvature it meanders as it follows the river. There's little to see, but if you shine a Flashlight up to the left you may catch a glimpse of a picture of a Skaarj wearing a pirate hat with scrawled nearby "Pirates of Naliland". Curious.
The boat will come out of the cave and dock at a jetty in front of a turning windmill. Climb out of the boat and on to the jetty.
Note: If you fall off the moving boat and into the water (doh), then you'll have to swim the distance. There are no hazards, barring a few Devilfish in the water near the windmill dock, it's just tedious. At the dock, use the sloping ground to climb out of the water.
Leave the jetty and go along the stone walkway to reach dry land. If you need ASMD ammo, drop into the water and swim behind the main jetty support pillar. There's a doorway in the back which will lead you to a cubby hole with an ASMD. At the windmill, go to the right to collect a Nali Healing Fruit before going round the side of the building to the left. Enter the windmill through the side entrance.
In the windmill foyer, an Eightball Gun is near a broken corpse, and a chest nearby contains a can of 12 Eightballs. When you have the gear, switch to the Eightball Gun and go down the cellar steps opposite the entrance. Kill the SkaarjGunner with an Eightball Gun who is lurking in the room then go into the room itself to collect 40 Tarydium Shards from the corner by the stairs (I recommend you use Eightball grenades bounced down the stairs for this one).
Leave the windmill and turn right. There, an arch leads into a small graveyard. Open barrels on this side of the arch for two Nali Fruit Seeds, then go through yourself.
Enter the graveyard. Collect the Nali Healing Fruit from the nearest grave, then go further towards the back on this side of a fence to the right. There is a smaller gravestone there (you may need a Flashlight or Flare to see it) which carries a message:
Here lies Haith M'olner, may his soul soar high with the gods.
Go to the back left corner of the area for another Nali Healing Fruit and a can of 12 Eightballs. You've done all there is to do here now, so go round to the other side of the fence. You will see a cave entrance to the right - go through to the cave beyond to exit the level.