These are the tricks and methods that I used to complete the challenge "Don’t touch any water" starting at 5-1: IN The Wake of Poseidon.
 

Draining the water

Without draining the water first, it's impossible to complete this challenge. You must remove 3 iron valves from the beginning of the level to complete it.
 
 

The first one is found right at the beginning.

 
 

 
 

The second one is hidden within a small cave. Its entrance will be partially hidden on a wall facing the door from which you came.

 
 

 
 

The last one is in a hole on the wall facing green hookpoint.

 
 

 
 
The following message will appear if the last valve is destroyed.
 
 

 
 
However, there will still be some water for you to avoid so here are some tips I used to make this challenge easier.
 
 
 

Collecting Skulls

Main room

 
 

 
 
Kill all the enemies in this region. I recommend killing the Virtue using the Railgun for a quick kill or the Rocket Launcher if you already have it. After you have killed all the enemies, it is time to collect the skulls and unlock the main entrance. Use the hookpoints for protection from the water.
 
Given that the arena surrounds water, it is highly recommended to start with the right entrance.
 
 

Right room

 
 

 
Here you will face a Malicious Face, two Cerberuses, and a Fighting Face.
 
 
This trick will quickly eliminate the Malicious Face. (Whiplash-Pump Charge+Knuckleblaster-Ground Slam)
 
 

 
You can kill the Cerberuses however you wish. I find it easier to use the Overheat Nailgun, and the Electric Railgun.
 
 

Left room

 
 

 
The left room has water in part. You can use the hookpointgs in order to kill the Virtues, which will spawn on the top plataforms. Use coins to kill the Soldiers and Strays, and the Piercer Revolver to kill the Malicious Faces. Long-range weapons such as the Railgun or the Piercer Revolver charged shots can be used to eliminate the Malicious Faces and the Soldiers.
 
 

Middle room

 
 

 
The middle room is the easiest area to not touch water. There are many Streetcleaners and eventually, a Virtue will spawn. Be sure to go after the Virtue, as fighting a Mindflayer with a Mindflayer can be very difficult.
 
 
 

Finalizing the level

The rest of this level is quite dry, except for the last big room with puddles and water, which you might accidentally step on.
 
 

 
 

 
 
Kill all enemies and you'll see this fancy yellow textbox after you've completed the level.
 
 

 
 
After all that time without touching water, it's time to hydrate. Drink water. Now.

 
 

 
 
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