Underwater case for flashlight

Hi all

I'm looking for an underwater housing for flashlights (for up to ca 40m depth, everything above 10m would be worth a remark too ).

I need it specifically for a Dereelight DBS V3, but as it seems that there is no product from dereelight itself, I am also interested in products of other manufacturers (possibly they will fit my dereelight too). I was already searching using google but didn't find anything. Also, neither on the official website of dereelight nor on flashlightconnection.com where it has several dereelight accessoires.

Is there anything similar to the underwater cases like

http://www.letsbuyit.de/product/195...-wp-dc500-unterwassergehause-fur-die-ixus-330

for flashlights?

Basically it would be enough to have a plastic cylinder of a certain length with exactly one button at the back to operate the forward clickie.

Thank you very much for any hints, ideas on how to make such a case myself or other related comments!

Cheers, Simon.

Pressure will attempt to hold the switch in and collapse the window. If you're at flashlight-body-collapsing-depth, then you're in trouble anyway. If you're at shallow depth a ziploc with the air squeezed would work, but as you go deeper you might not be able to turn it off reliably. Clearly this would affect the beam pattern slightly. At some depth the window might be damaged without reinforcement against pressure.

If you don't mind a bit of DIY, this wouldn't be hard. All that has to be clear is the front cap, and you just cover the little plunger that reaches through the PVC pipe and other endcap with rubber. This would NOT allow heatsinking.

PVC endcap with hole drilled for plunger to push switch
Plunger to push switch, cover the outside end and endcap in rubber sheet
PVC pipe to length
Clear, thick plexiglass on the end

Many flashlights are fairly water resistant, I've swum with my Quark. But diving would force water into the reflector and battery compartment, at least.

I think most divers expect waterproof flashlights, so there's not much market for waterproofing. High-power lights also overheat in plastic boxes. Try a ziploc, and watch for heat.

I'll leave your thread here for a while, but it may fit better in our Dive Lighting sub-forum, depending on what you decide to do.

I agree. The market for waterproof flashlights won't be big. As I do not dive that often and as I have a very good and strong light, I don't want to buy a new one

So, probably I'll stick to the DIY solution. I've already used a ziploc for snorkeling, but I never tested it in deep water - however, it worked fine. I think it would not be very easy to construct a good hard case. So I'll start looking for a stronger plastic to improve the ziploc-solution.

I just had the thought, whether the light would not be waterproof for deep water anyway? I mean, the tailcap is protected by a fine thread with two O-rings. The lense has one big O-ring but very well integrated (like a labyrinth). The metal body won't be a problem anyway. So, two bottle-necks still exist:

1. the push switch won't be leakprof, I imagine and
2. how much pressure will the lense be able to resist?

To fix the first issues, perhaps filling up and covering the push switch with silicone could help. Water pressure would then just press the silicone on the switch.

The second issue... well. I've a second lense. Would it help to put them on each other and perhaps to lumb them together? Haha

Has anybody tried that or tested the durability of such a lense?!

I think the problem with doing a double lens is that if the pressure is great enough for water to sneak through the first lens, the second lens won't be able to hold the water back either. While 2 lens together are more resistant to breaking, breaking is not the issue its the o-rings.

Most light-o-ring combos are tested at 1m for some minutes. This amounts to about 0.1 atms of pressure. The problem with that measurement is that it tests static, not kinetic pressure.

The plastic bag idea is the simplest and most cost effective IMO. If your worried about it leaking take a look here:

http://goinggear.com/index.php?main_page=product_info&cPath=76_55&products_id=697

This bag is rated to about 6 atms of static pressure.

You're better off just buying a dive light, as it does what it was intended to do reliably.

I personally don't go diving, but if I had to the Heliotek HTE-1A would do the trick for me.

We're tossing off all this stuff about pressure, but here's the diver's rule of thumb. Each 33 feet of water (10m) adds another atmosphere of pressure. So at 0ft you are at 1 atmosphere, and at 11ft underwater 1.33 atmospheres. 1 atmosphere is 14.7 PSI.

A completely waterproof light will keep 1 atmosphere inside it while the outside pressure rises. This pressure will be trying to force water past the O-rings, and crush the aluminum walls, and the glass. You'd better not have to worry about the aluminum, but once you have a 2-atmosphere differential on the window, that pressure adds up. As you bring the light down through the water, keeping water our requires increasingly tight tolerances and strong windows.

If you go with the ziplock bag but worry about the window, you can always put a (very sturdy! It'll be holding the pressure now) clear end cap that rests on the bezel. Mind the heat, as always.

AnAppleSnail said:

We're tossing off all this stuff about pressure, but here's the diver's rule of thumb. Each 33 feet of water (10m) adds another atmosphere of pressure. So at 0ft you are at 1 atmosphere, and at 11ft underwater 1.33 atmospheres. 1 atmosphere is 14.7 PSI.

Click to expand...

+1, thats a good rule of thumb. That stems from the fact that acceleration due to gravity is 9.8m/s^2 or 32ft/s^2. To take into account dynamic pressure you can simply take (v^2*density)/2 and add it to the gauge pressure. Just be sure your working in the same units when you add.

I don't think the window will break before the light flood and equalizes the pressure anyway. The shape of the window will help keep it from breaking and the glass should take a beating before cracking.

I'd worry with sapphire since its more brittle than glass.

At the depths you mention, I would be concerned about the external pressure compromising the window of the flashlight. If the external surface of the head is smooth, I would think you could come up with a delrin or plastic cap that had a much thicker and sealed window that could slip over the flashlight head with its own seal to head. This would isolate the flashlight's window from the external pressure. Some form of condom or plastic bag could then be used to shroud the light. The external pressure will collapse any type of plastic shroud around the light just like a vacuum bag does and this would put the plastic in contact with the light and improve your thermal path to the water. If you have ever dove in a dry suit, you have experienced just how well the external pressure collapse the suit about your body!! You don't notice this in a wetsuit because it floods and allows the collapsed neoprene to float around you as opposed to being compressed against you.

It is not possible to encase a light for underwater use. Even if you could make the enclosure waterproof. The light would not be able to cool and would fail when you need it most.

For diving you need a dive light. It is sometimes possible to use a dive light out of the water. But even this is not always true. The design may depend on immersion for cooling.

Some lights have been designed from the start for both underwater and surface use as the AELight 35-50.

aehaas

AEHaas said:

It is not possible to encase a light for underwater use. Even if you could make the enclosure waterproof. The light would not be able to cool and would fail when you need it most.

.....
aehaas

Click to expand...

I agree that there are thermal conditions that need to be addressed and especially in the cases of light that drive the LED's hard but to say it is not possible to encase a light for underwater use is simply untrue, IMHO. I can imagine some enclosure designs for topside lights that would be waterproof and afford the light better thermal relief under water than it enjoys being hand held, topsides.

Hm, I see.. it's not that simple. After reading here and speaking to my dive master, I think I'll buy a dive light and keep my DBS for normal usage. Even if I could make my light waterproof, it would not be that effective and suitable as a dedicated dive light.

So, I'll check the dive light forum for the optimal specs of a dive light. My preferences are an LED emitter (fast turn on/off -> no HID), a good ratio between size/weight and light output and I think more throw than spill is better under water. But I don't have much experience so far (did one night dive with an old halogenous incandescent light). I'm looking for a "hand light" - like a DBS neither a big light with extra handle nor a small backup light. Something in between.

If you can recommend a light - please do so. But I also will start searching and looking around.

Thanks, Simon.

I've found one

Looks greats! But I've some questions to it... see

https://www.candlepowerforums.com/posts/3441323#post3441323

If your worried about heat, don't. The main method of heat transfer in air and water is convection where the movement of the fluid carries away heat. Since water is denser than air convection will work better, not worse. Conduction from holding the torch should work the same.