This 3350 Lumens Dive Light Diving Flashlight is a SUPER BRIGHT light with a 300 meter beam. It has 3 lighting modes that require turning the head for on/off, and the 3 modes (no button).
The stainless steel and aluminum body are tough, and impact resistant. It's also rated IPX8 waterproof and comes with extra seals, and a little container of what looks like petroleum jelly. The instructions don't mention what the jelly is used for, but I'm sure divers may know - obviously for added waterproofing. I got this to use on outdoor adventures and spelunking on dry ground. This can be used for underwater photography.
This has a super powerful 21700 lithium ion industrial battery. I was surprised that the battery itself has THE charging port on it; it's the only way to charge the battery. I'm torn 50/50 on whether this is brilliant, or potentially super dangerous. You decide.
I personally will NOT be exposing this flashlight to water, much less salt water. But, that's me going into mom-safety-mode, and being over protective, I'm sure. My personal opinion only.
You have to make certain the seals are good and waterproof before diving with it. This Flashlight will certainly illuminate dark underwater areas, and is great for hiking, climbing, and spelunking in the dark.