This type of battle ground is comprised of many tall trees (>10m) within close proximity to another. Sparce trees (i.e. greater than 20m apart) do not fall into this battle ground category. In this type of environment, one's line-of-sight is minimized due to the amount of trees and vegetation around. Water wars which occur in these forested areas involve a lot more strategy and use of the abundant hiding places.

IN THE THICK OF THINGS
One thing to definitely take advantage of in trees are the trees themselves. Trees offer great hiding places and can allow one to sneak up on enemy positions or set up ambush spots. Be forewarned, the enemy can do this as well. The main difficulty is often getting one's bearings in a forest. A compass can come in handy if one's water war game is being held in a large, forested area.

When traversing between trees, one must watch one's footing and listen to the sounds about. Tree roots and fallen branches are both a tripping hazard as well as a potential noise maker which can give away one's position. Dried leaves should also be avoided if one wants to minimize the noise one makes.

When hiding or ambushing, firing a stream of water from behind a tree is a fairly simple task. A common technique is to glance, fire, then return to one's hiding position behind a large tree trunk for protection. However, if engaging multiple hostiles, be wary in case they attempt to circle the tree in both directions. In that case, one can find oneself surrounded very quickly.

USING THE VERTICAL
If one is a confident, experienced climber, and the trees are large enough, one can often climb various trees to get a bird's eye view of the surroundings. Depending on the network of branches, one may even be able to cross from one tree to another but this is typically not a good idea. Attacking from atop a tree if the line of sight is clear will definitely give one a distance advantage. Take note, however, that one must climb down to escape. Thus, it is often not a good idea to attack unless the hostiles are far enough away that one will have enough time to climb down and escape after firing.

I THOUGHT A HEARD SOMETHING...
In the depths of a forest, one must rely as heavily on one's hearing as one does on vision. This fact can be used to one's advantage. Throwing a small stick or rock in another direction can send a nearby hostile investigating the source of the noise as opposed to where one may be hiding. Distracted hostiles are more easily surprised and soaked than those who are on their guard.

MIND THE VEGETATION
Trees are living things, believe it or not. As such, try to be nice to them. Thankfully, the ammo used in water fights will do a great job in feeding them. However, avoid trying to force oneself through thick undergrowth, breaking branches, etc. Not only will this make a lot of noise but one is more likely to scrape/injure oneself in the process.