I've tried using navigation a few times since I got my watch and every single time it killed my watch super quick (~5 hr). Since I was on a long trip, I had ambient mode off, tilt to turn on disabled, maps voice speech off (which kills the buzzing on the watch when a turn comes up), I just wanted to be able to tap the screen and see how many more miles I had. There was minimal difference between having those 3 features on and having them off while using navigation. The watch also got warm the whole time, every time i've used navigation.