I think that if you can't count on the reliability of the equipment, then you should migrate toward a different model or brand. Up here in the Monterey Bay, I don't think I have seen a single diver with a Hollis light. Nearly everyone dives with a Light Monkey, Halcyon or an occasional Underwater Light Dude.
Your light is your voice underwater. I consider it an integral part of my dive equipment, which I carry on every dive. I don't want to worry about its operation. I haven't seen the Halcyon Focus underwater, but I was quite impressed by its output, topside. Personally, I use a LM HID 20 -35. I can set it to have a lightsaber focus of a very even wide focus, which wont blur my Go Pro. If you want compact with super high output, then the Underwater Light-Dude lights are hard to beat (definitely not as focused as an HID).
O.
Your light is your voice underwater. I consider it an integral part of my dive equipment, which I carry on every dive. I don't want to worry about its operation. I haven't seen the Halcyon Focus underwater, but I was quite impressed by its output, topside. Personally, I use a LM HID 20 -35. I can set it to have a lightsaber focus of a very even wide focus, which wont blur my Go Pro. If you want compact with super high output, then the Underwater Light-Dude lights are hard to beat (definitely not as focused as an HID).
O.