Okay I have a tough flashlight question - even for the jaded...

I play disc golf. In this game you have water hazards, and sometimes discs go in water. I've lost a few that way.


Today it happened again, but I had my Surefire 6P with an M60 with me. Don't usually EDC this light most the year, but since it's near December I've been packing it.


"Unfortunately" a bunch of other players were around and immediately started scraping the "creek" (it's actually only about 8 feet wide and barely has any flow) with sticks to help me out - normally this would be a very nice thing...


But this time that tactic wasn't helping. Had to return 20 minutes later after the "silt" settled down in order to use the light.


Shoved the light 2 feet under water, then from air, found my disc. It wasn't the money ($15 bucks), just that it's one of my best discs, and I know it well. Would have spent an hour in the water if I had to - and I did roll my pants up and get in, had to to get the light anywhere near enough to find it, and it was COLD!


I made a few "flashaholic observations" while doing this...


Putting the light underwater didn't really seem to help all that much, it was probably 99% as good just shining it from above. I'd thought going under would reduce "back-reflection", but that didn't turn out to be the case. I immediately realized that unless I was literally shining the light straight down from my eyeballs this wouldn't be a factor. And I don't think I was losing much in the way of lumens by aiming from the air. It was an "air shot" that finally found the disc...


But the thought in my mind now is this: Could there be a light (aside from the obvious factor of more lumens) that would be better suited for this? Should it be underwater or above?


I'm talking about somewhat dirty water with a max depth of maybe 3 feet, and finding something in it, but with my eyes in air. I'm not diving. If the water is perfectly clear then the choice is obvious - shine from the air. But with some cloud in there?


My gut instinct is saying "tight and bright thrower", and to the extreme. But should I aim for an underwater beam or over water? That's my real question - is there a beam profile that'd really "shine" (pun only semi-unintended) underwater that I should look into? Or is "what's good on land good in water" like my admittedly limited "water experience" seems to suggest?


This is not a question about flashlight models, I am speaking purely about beam profile here, and maybe even tint (for my first time)... (selecting a product comes later)


Let's not forget that while I'm bringing up the subject of underwater beams I'm talking about eyeballs above the water...

As you already found out your best bet is to disturb the silt in the bottom as little as possible. You are generally in the conditions as you described them going to have less water between your eyes and the object if you shine the light from air and since water is much more dense than air it's very unlikely you will have better luck putting it underwater.

A focused light with result in less backscatter and if you do put the light in the water just put it barely underwater to eliminate the refraction of going from air to water.

I have a 3 foot deep fish pond in my backyard. I can put a Surefire 6P with a XM-L in the water and by the time it hit the bottom I can't even see light. My pond has a lot of plankton. Your puddles probably don't but once the water becomes muddy viability is almost zero. I know that from diving in such water.

So disturb the water as little as you can and try to locate the disc from the air and if you must just barely put your light below the surface. That's my 2 cents

As gcbryan says, backscatter is a far worse problem underwater than in the air. You'll hardly ever find water where there are no suspended particles, and any disturbance can kick up silt etc that can then take ages to settle. To minimise backscatter, use a tight (not floody) beam and keep the light source distant from the angle of view (hold it well out to one side). If you wonder why u/w cameras use long extension arms to keep lighting systems out to the side, backscatter is the reason.

I disc golf also, and I started playing over 15 years ago. I have played courses in Nebraska, Colorado, Oregon, Washington, California, and even Canada...

My advise is, most importantly, ALWAYS watch where your disc goes. Mark the spot where you threw from, and pick a landmark near where your disc goes out of sight, and walk towards it!

Get some polarized glasses!!! They cut down all the glare from the surface of the water and you can see 20 times better. They are like magic.

If the creek is flowing, always start downstream and slowly make your way up, kick up as little silt as possible.
What you do kick up will be carried downstream, where you have already looked.

Get orange, pink, yellow, or white discs. They are A LOT easier to find. Do not buy any more discs that are black, brown, grey, blue, red, or green (duh.) Also, red is the first spectrum to disappear underwater. Ever see red fishing line? That's why it's red!
Almost all my discs are yellow or orange. (I have around 20 discs.)

I think a flashlight would increase the glare, and only make them harder to see.

On a side note, I went swimming in a pond to get a (favorite) disc of mine once...
I came out with like 6 or 7 discs!!!

Sorry, if I totally missed the point of the flashlight related question here...

This is just a thought, but couldn't someone design a disc with a 5mm LED and a coin battery in the middle (to keep the disc balanced), so you can find it at night easier (and would probably even help in water!). Another idea would be to have reflective or fluorescent strips of tape or something on the disc, to make it more visible.

~Brian

Not necessarily what you're asking, but if you're looking for something white/flourescent, wouldn't a nice blue/UV light help highlight that item??? I have an old blue flip-up SF filter ("F" model, not "FM"), and it really highlights any white, FL items...makes them "glow" if you will...

You might consider putting a dab of flourescent paint on the top of the disc (although I have no idea if that is against the rules of play). Reflective paints of the type that adorn stop signs and reflective clothing strips worn by highway workers hugely reflect even the tinest amounts of incident light. Presumably this feature might improve the reflectivity of your disks underwater. (You should of course try this as an empirical experiment, before adorning your disks.)

Best of luck...

Thanks for all the replies, kind of disappeared from my own thread here due to unexpected holiday activity, now it's back to real life and back to night disc golfing too lol!

what about putting a light on a pole? a thin sapling, bamboo pole or even a dedicated fold up fiberglass tent pole... you could move it around to the side, high overhead, poke it around under water while viewing from well above, etc, even work out a two or three fingered grabber on the end with a pull cord.