With the dive light you mentioned... there are many that look the same, but some of these MAY NOT be the same quality. recently I bought a couple from Yupard on AliExpress which I disliked. Mainly because tail cap current was like 1.5A driving the XM-L. It was a much weaker output than I was used to.
The first one I bought was an Aleto from aletocn. I wrote the seller a couple weeks ago and he says... The light is 2.50 aMp when it is draws on High. - I used a 26650 KingKong cell and drew 2.6+Amps. I don't know what he tested it with.
I also read the review on BLF re. this light from DX. "_the_" stated ~3.0A from his. I think they're probably the same.
So if you get a good one it will be pretty bright. If not, then I would like to know who you bought it from.
Also, I believe the magnetic switch will rust out if used in salt water often. There's a magnet, spring, and tiny ball bearing behind the black plastic twist switch that will all corrode quickly - I have only used mine in fresh water so I haven't seen any rust which they say will happen.
I like the light, but use it in fresh water only.