I originally bought my blf A6 for work more than 5 years ago. A month or so back, it was finally swallowed by the sea while I was helping some flipped kayakers.
I’d just replace it, but the only one I’ve found was >$60 on Amazon…
Is there something similar out there nowadays that’s bright, small, and a single 18650 flashlight?
Or does anyone still have a source for an A6?
If you’re referring to the BLF A6, try a Convoy S2+ and don’t look back.
… and welcome to BLF.
There is sooo much choice, it depends what you valued in the A6.
You can stick with a tailcap or go for a sideswitch, or both, you can get built-in charging, you can go floodier, throwier, higher CRI, different colour temps, triple LEDs, a more hot-rodded impressive but impractical max output or more regulated, sensible modes, fixed or programmable modes.
You can go shorter with a side-switch, wider with a 21700 battery, soooo many options. (Just remember that in general the bigger a host the better able it is to handle heat.)
Or you can just try and find something exactly the same, sometimes when something just works for you there’s no reason to change. Your call.
+1 
Convoy S2+
It just worked for me, but here’s what I loved.
18650 (since I have a ton)
Small (fit in my pocket)
Fairly watertight (since I use it around saltwater)
Reliable and Sturdy
Good throw
And thanks for the welcome! Also for the recommendations - it’s given me better search results here. Now to decipher exactly what to order and where. I’m looking at the 6500k SST-40 I think.
Are there recommended sellers here?
I didn’t notice it was your first post, welcome! 
Was the A6 throw adequate? IIRC it has an XP-L emitter, the SST-40 will be similar but brighter while also drawing more power and running hotter on max.
An SFT-40 will be similar to the SST but throwier (it’s a SST-40 without the dome), and you can get much throwier LEDs that that such as a an Osram CSLPM1.
Edit:
Here is a list of S2+ that people have mentioned: Convoy store S2+ search
and here is it with an SFT-40 : Convoy S2+ SFT-40
which has a regulated max mode of 5A, which is similar to max mode on the BLF A6.
I find the S2+ to be a little more slippery to hold than the A6 but that may just be because it doesn’t have a clip. You can buy a clip though, and/or a lanyard if that’s convenient for how you use it.
From a beam pattern point of view the SST-40 and XM-L2 will be similar to the XP-L in your A6, and will be similar brightness to the naked eye. The SFT-40 and XP-L HI will be pointer as they are the dedomed versions, the SST-20 will be slightly pointier still and you’d notice a reduction in the spill amd will be slightly less bright overall, an Osram CSLPM1 even pointier, and an Osram CSLNM1 very pointy indeed 
I’ve not experienced the Nichia 519A and don’t quite know where it fits in, the Nichia 219B will be similarish to an XP-L Hi but will be much less bright as it’s the price to be paid for the quality of the High CRI beam.
The LH351D will be similar to the A6, and a 5700K High CRI version will be cool while showing up colours better.
This is just in the Convoy S2+ but will hold true for other hosts of similar size with a similar sized reflector, of which there are many.
One difference between the A6 and the S2+ is the A6 uses a FET driver, which means it became dimmer as the battery depleted whereas
the S2+ uses regulated modes so the brightness stays the same.
It also means that the A6 max mode effectively connected the battery straight to the LED, so different LEDs would draw different currents dependent on their characteristics, and some LEDs simply wouldn’t be suitable for this kind of driver, whereas with the Convoy drivers the max current delivered will be the same for all LEDs as long as they can handle it and the battery can provide the power.
My instinct says that the SST-40 would work for you, and that i would look at the 5700K LH351D for better CRI (better colours), or the SFT-40 for more throw as i would personally choose both of those over the SST-40.
The XM-L2, XP-L, and XP-L HI (all Cree LEDs that predate the SST-40) would also work, especially if you want a different colour temp or tint, some people can find the SST/SFT/LH351D a bit green but that’s personal taste, and the XM-L2 has quite noticable tint shift which you may not like.
That info is just for background info really, hope it’s not too much.
Too much? Marc E, you’re killing it!
So I’m buying 2, and I’ll gift my least favorite to my coworker since either will kick his flashlight’s ass.
Now I’m leaning toward a high CRI, and a high throw. I’ll be primarily shining them into the ocean, and I’m curious to see how the tint affects how the sea life looks.
Maybe a nichia 219b 4500k for high CRI, and an SFT-40 for high throw?
Mateminco sells the A6 under their name
https://www.aliexpress.com/item/32872224134.html
Personally i prefer the A6 design over the Convoy S2+
fw3a
much smaller
just as bright
many more features
wle
In that case, buy a Emisar KR1, or Noctigon KR4 which is built better.
i will also say that my favorite light before fw3a, was the BLF-A6
i still enjoy it with an 18350 tube
it;s my 2nd favorite
but the FW3A is that small, with an 18650 battery!
the A6 wastes a lot of length on its conical reflector, and the tail switch
with an 18650, it is just too long for comfortable pocketing
wle
I’d read the FW3A is floodier than the BLF A6. I don’t have any experience with one though.
it is but not that much
i like a bit of floodiness
wle
I hated the A6 (first series, monday morning product) while others loved it.
Never had any trouble with my (also first series) FW3A. It’s only flaw was sloppy assembly. From this light I learned that every new light that lands on my doorstep needs to be inspected, cleaned and (if necessary) re-assembled.
It is said that with every new batch that is made, the manufacturer cuts an extra corner. So today the quality of the FW3A seems not to be the same as it used to be.
I would go for the Convoy S2+ with SFT-40 led. It has a 5A driver.
Same advice.
whereas i have a convoy s2+ and do not like it because the beam is way too spotty for me
Nice!
I prefer the A6 over the Convoy S series as well. 
I’d vote the S2+ also, but I’d give serious consideration to the newer 21700 cells if you don’t mind buying new cells and/or if you might want more run time. The S21 is the same light with the larger cells…just slightly larger in the hand, good feel to it.
I’m wondering if you’d really like that light with something like an SST-20 in 3000K. It’ll have a tighter beam than larger emitters like the SST40/XML…not sure if the warmer temp would be nice or dull in ocean water, though. Does colder white make sea life pop with color a little more?
Pretty bombproof light. Probably pick up some spare o-rings when you order…he’ll include them for free if you ask or leave a note. Usually sends a spare set with the light but since they’re not easy to find in any hardware store I’d keep a bunch extra and store them well (body tube rings and lens ring, both).
The Sofirn SC31 Pro is something else to consider. Nicely built, has the Anduril ramping firmware with a side switch instead of just stepped modes with a tail clicky. I don’t know if it’s truly reliable with water, though.
If you want something similar to the A6, I actually recommend the Convoy S3 with the SST-40:
https://www.aliexpress.com/item/1106058070.html
Very bright, decently throwy, better thermal design, and tons of modification potential
If you want an A6 clone, that’s one thing.
But pick out what you want first: tailswitch only / sideswitch only / both; UI; reflector vs TIR lens; flood vs throw; color temp; CRI; etc.
There are so many options out there that once you figure out the checklist, you can get pretty close to what you really want.