If this is fully submerged in water like...
If this is fully submerged in water like on a river trip will the bag keep my gear dry???????
For a short period of time, but I wouldn't expect it to keep your stuff dry for very long. Even the best waterproof pack won't take a prolonged soak. The more dependable- and common- way to keep your great dry is a waterproof pack liner or dry bag.