Review on Wurkkos 13000lm Scuba Diving Light: Ultimate Waterproof LED Submarine Flashlight for Outdoor Adventure - Includes Batteries! by Brandon Roberts

I've used this on 3 dives, 2 at the Blue Grotto and 1 at Devil's Cave. All three dives lasted about 3 hours and 50 minutes. At the end of the third dive, the flashlight was not consistently operating at maximum brightness. I find it perfectly acceptable for this time with the brightness of this light. The light is very bright at full setting. I can't verify if it's 13,000 lumens or not, but it's definitely brighter than my 1200 lumen bulb. I ended up sending the flashlight back because it didn't work for me, or at least for the type of diving I do. It was almost impossible to see anything under the 13,000 lumen light. The beam was too wide and just illuminated all the particles in the water and reflected them back at you. I ended up spending a lot of time with it at low to medium brightness. If so, I want a smaller light because this thing is huge. It's very long and I don't like holding the flashlight all the time, I like tying it on my wrist. It's possible with this light because I did it, but it was uncomfortable. My main dive light is a large blue 1200 lumen flashlight. It does the job very well. I wish I could have more lumens, but 13,000 was overkill in my opinion, especially the way it refracts the light back at you.