Combat AI: do not use range weapons under water

apps/openmw/mwmechanics/aicombat.cpp

@@ -535,6 +535,10 @@ namespace MWMechanics
         // opponent's weapon range, or not backing up if opponent is also using a ranged weapon
         if (isDistantCombat && distToTarget < rangeAttack / 4)
         {
+            // actor should not back up into water
+            if (MWBase::Environment::get().getWorld()->isUnderwater(MWWorld::ConstPtr(actor), 0.5f))
+                return;
+
             mMovement.mPosition[1] = -1;
         }
     }

apps/openmw/mwmechanics/aicombataction.cpp

@@ -118,7 +118,19 @@ namespace MWMechanics
         float bonus=0.f;
 
         if (weapon->mData.mType >= ESM::Weapon::MarksmanBow && weapon->mData.mType <= ESM::Weapon::MarksmanThrown)
+        {
+            // Range weapon is useless under water
+            if (MWBase::Environment::get().getWorld()->isUnderwater(MWWorld::ConstPtr(actor), 0.75f))
+                return 0.f;
+
+            if (enemy.isEmpty())
+                return 0.f;
+
+            if (MWBase::Environment::get().getWorld()->isUnderwater(MWWorld::ConstPtr(enemy), 0.75f))
+                return 0.f;
+
             bonus+=1.5f;
+        }
 
         if (weapon->mData.mType >= ESM::Weapon::MarksmanBow)
         {