Its a great reliable light, but I found it quite negative for the runtime and brightness. For an hour long dive that just requires a cordless handheld, I might suggest something smaller and lighter with a single replaceable 21700 cell rather than the 4 18650 cells the SD01 packs. In my opinion, not really worth dragging the extra cells up and down (and messing with trim) when a battery can just be rotated out back on the boat or shore between dives. For dives requiring longer runtimes, there are now decent quality canister lights to be had in the $400 range. I used and enjoyed that Sofirn SD01 for dozens and dozens of dives, but utimately it never fit any real niche so I passed it down to someone who was just getting started in diving.