Underwater torches/flashlights

[milktrayman]

I recently bought a new back-up light ready to go on a Night dive, when I noticed a bit of a design fault..... why have torches which turn on by turning the top.. you turn it too much underwater and it opens up.... and water goes inside the torch.. clever! erm... i think i'm going to buy one with an on/off button...

 

[Dive-aholic]

My first back up was like that and I thought the same thing. Never had a problem with it. I did end up replacing it with an Ikelite PCa that has an on/off switch. The head doesn't stay on very well and has flooded already because it came loose on a dive. The UK SL4 is a better design. The head is screw on, but separate from the on/off switch. I've already gotten rid of the Ikelites. When I get a smaller back up, I will probably get the screw on/off. You only have to turn it about a 1/4 turn to turn it off.

Besides, once you turn it on, you don't want to turn it off because it might not turn back on! Once it's on, it stays on until you get out of the water.

 

[Marek K]

Ikelite PCa that has an on/off switch. The head doesn't stay on very well and has flooded already because it came loose on a dive.

Several people have had the same experience with the PCa, to include me; see this thread. Specifically, my experience in Post #18.

The PCa is just a bad design, as far as its opening. Man, I do love its light quality, for the size and price!!

I agree that a light with screw on/off switch is more sturdy... don't know about more reliable... You just have to remember which direction is "on"!

--Marek

 

[miketsp]

Separate on-off switches (unless they are the magnetic type) represent an extra potential failure point. All my dive-light failures to date have been from water ingress at the on-off switch. It's normally the only part you can't dismantle and lube.
Those with a screw-down on-off mechanism normally give you quite a safety margin - at least a couple of full turns after turn-off before any water will get in.

 

[The Kraken]

The Off/Flooding syndrome just attacked my wife's Pelican SabreLite LED.

In order to turn the light off, she had to rotate the head to the point that it flooded.

Back to the LDS for replacment.

the K

 

[dbg40]

I use the Halcyon scout lights, wich has the rotating on off switch. This type came from too many failures from mechanical on off switches, and is pretty fool proof. You just have to be familliar with it before diving with it. You don't have to get nuts with the twisting, I know that mine have to cranked out pretty far to make them leak. All it takes is a quick twist, and it's on or off, switches have a habit of dissapointing you when you least need it! and a back up should be as simple as possible, with the fiewest possible points of failure. Although costly, buy a good one if you can afford it, The maker of a lesser quality light may replace it with no trouble after failure, to my way of thinking, the failure in the first place was the trouble.

 

[Scottri]

I've had PC lights for years and I've never flooded one yet. I prefer an on/off switch but I have a mask light that rotates the bezel to turn it off and on and I haven't flooded it yet. I really like Pelican and UK lights. I'm not a big fan of Princeton lights. Every one of the them has either flooded or broken over the years so I don't buy them anymore.

 

[Charlie99]

..... why have torches which turn on by turning the top.. you turn it too much underwater and it opens up.... and water goes inside the torch.. ..

I used a paint marker to put a line on the black bezel of my UK Q40 light. It's on the top when fully screwed in/on. That lets me see how much I've rotated it when turning off. 1-1/2 turns off still has a good seal, and avoids the other problem --- the light turning on at depth.

So far my PCa lights have worked well for 100 or 200 dives. Super bright for the size. As suggested by a dive shop, I press the lighthead into the body when undoing the latch, thereby not rounding off edge on the latch that hold the lighthead in place.

 

[Dive-aholic]

Several people have had the same experience with the PCa, to include me; see this thread. Specifically, my experience in Post #18.

The PCa is just a bad design, as far as its opening. Man, I do love its light quality, for the size and price!!

I agree that a light with screw on/off switch is more sturdy... don't know about more reliable... You just have to remember which direction is "on"!

--Marek

I checked out your post and I don't think it was the hydrogen build up. I just used regular disposables in mine and it still popped off. I'm using a canister light now. My 2nd primary is an SL6, and my back up is an SL4. Both great lights.

If anyone knows of a good light smaller than the SL4 that has a switch similar to it, or a twist on/off, let me know. I do need to replace my PCa.

 

[Marek K]

I checked out your post and I don't think it was the hydrogen build up. I just used regular disposables in mine and it still popped off.

I'm convinced it's an over-pressure problem of some kind, and hydrogen build-up seems to be the most-likely culprit. Though from what you're saying, it may not be because of rechargeable batteries, but just any kind of batteries.

Hydrogen does build up in sealed flashlights. The PCa's instructions warn about hydrogen build-up from batteries of any kind; though the warning is because of combustion danger, not over-pressure.

My experiences are consistent with an over-pressure problem popping the light head off, or wanting to. First, the light head coming off in my BC pocket... OK, that could have been operator error, but I don't think so because of the other evidence... like the damage to the locking lugs, and the over-pressure *pop* I heard another time when opening the light up.

In any case, good as the light is, I still think the PCa's locking mechanism is a bad design.

--Marek