The brightest flashlight that uses AA batteries is the Nitecore Caveman EA81, which shines at 2000 lumens. It takes eight AA batteries and costs about $120. It’s waterproof to IPX-8 Standard (1.5 meters) and impact resistant to 1.5 meters. The Nitecore Caveman EA81 is available on Amazon for about $135. I recommend powering this flashlight with low-discharge rechargeable AA batteries.