Lighting and Depth

[ScubaBeez]

Hello Everybody

I'm still fairly new to the whole diving bit and I'm hoping to learn more about lighting as it relates to depth. At what depth (during a day dive) do you find it starts to grow dim enough to warrant using a dive light? Obviously viz as a whole plays a part in this equation. If the water is murky less light will be able to travel through. The ocean around me seems to be as clear as New England water can get and I can't foresee having issues. I was, however, interested a "pond" near by that drops down to 80ft which is surprising for its tiny circumference. I can imagine it has a nice soft silty bottom and I wanted to be prepared if I was going to need some candle power.

Also on the same topic, what kinds of dive lights do you find work best? I'm thinking about a rechargeable one. Flashlight style or spotlight style?

I appreciate all the knowledge flowing around here. I'm sure I'll be posting much more often now that the weather is starting to get warm enough for my wimpy self to get back in the water.

 

[MSilvia]

I'll routinely use a photon torpedo "backup" light for looking under rocks and so forth, even in shallow water. I think it's one of the best "flashlight style" lights out there, and even cave divers like their reliability and performance. I'd recommend starting with something like that, because while it's about the same price as some of the bigger hand-held spotlights, and less costly than some of the closest competitors, it's very bright for it's size, and is unlikely to be something you'll outgrow regardless of the direction your future diving takes. Even if you someday end up going after a $1300 cannister light, you'll probably still be bringing the torpedo with you. Generally speaking, high wattage HID cannister lights (not to be confused with the hand-held HID flashlights) work best, but they are very costly.

Oh yeah... I run mine on rechargable NiMH batteries. I have both the incandescent and LED versions, and I think the LED is worth the extra cost.

On a bright, sunny day in typical conditions in New England, you'll probably be able to dive to at least 40 or 50 feet before "needing" a light. Naturally, that varies quite a bit. I've had pitch black at 30 feet, and rays of sunlight at 90. I bring a light with me on every dive, whether I expect to need it or not.

 

[Joe-Diver]

The first thing you should do is find some local divers familiar with this pond and get some info about it. Something with a small circumference that is 80' deep is unusual. It could be anything, from a sinkhole to a collapsed cavern to an old quarry. In these types of things you will normally encounter complete darkness at the bottom and pass through several thermoclines to get there. Full suit/hood/gloves plus lights and maybe a reel would be expected. There's no tellin' what's down there. It could be a very dangerous dive. From your profile, an OW diver with less than 20 dives, this is probably beyond what you're ready for unless you go with experienced divers familiar with the site. Even then, it doesn't sound like a dive you should consider just yet. Of course, you could always go with them but stay shallow, working your way to the more challenging part of the dive through experience and training.

....I was, however, interested a "pond" near by that drops down to 80ft which is surprising for its tiny circumference. I can imagine it has a nice soft silty bottom and I wanted to be prepared if I was going to need some candle power.....

 

[nolatom]

Here's another reason to carry a light, or two. As you get deeper, the long-wave colors (red, orange, yellow, green) can't penetrate and all colors become gray, blue, or violet. Your light will bring out the brighter colors.

I'm old-school, I carry a pocket-sized 4-AA light with a wrist lanyard on every dive, and a C-8 "radar gun" on night or low vis dives.

Generally, if you "need" a light on a dive, then you need a backup too, in case the primary goes out.

 

[MSilvia]

Something with a small circumference that is 80' deep is unusual. It could be anything, from a sinkhole to a collapsed cavern to an old quarry.

Good thought Joe, but there aren't many sinkholes or caverns in these parts, and the local quarrys rarely look like ponds so much as old quarrys. Still, it's good to be cautious. Mass Fisheries keeps depth contour maps of all massachusetts ponds online, so it would at the very least be a good idea to check it out in advance.

Full suit/hood/gloves plus lights and maybe a reel would be expected.

That's all pretty much a given for most dives around here. With water temps rarely in excess of 55 degrees, there aren't many who would consider diving without a hood. You'll probably be better off without the reel for now though, IMHO. I think it's a good idea to get your basic skills nailed before you start trying to deal with line.

It could be a very dangerous dive.

I'm not sure what the site is, but I'd guess that so long as you keep an eye on your depth, it's nothing you and a buddy shouldn't be able to handle. Out of curiosity, what's the pond?

 

[TSandM]

Where you need a light depends enormously on what the water's like. In Cozumel, at 100 fsw, there was enough light to read a newspaper. In Seattle today, at 40 feet it was as dark as a night dive. I can't imagine anybody diving today without a light.

In good ambient light, a dive light helps you look into and under things, and brings out colors. In poor visibility and low ambient light, it helps you keep in touch with your buddy and pass signals as well.

Points to consider in selecting a light are ambient light, water opacity, power and focus. High ambient light washes out less powerful dive lights, but you can overcome that with power and focus. Water opacity defeats even powerful lights if the beam is diffuse. Night dives in clear water require less power and can be better with a diffuse beam.

If you are diving in moderate visibility and low ambient light, and don't want to spend the money for a high power, high focus light, the Photon Torpedo with the LED module is a superb light. It has excellent burn time, a tightly focused beam, and a fair amount of power. It's hand-held and easy to stow, and as good dive lights go, relatively inexpensive. (That's coming from somebody who owns a PT, a $700 NiteRider HID, and a $1300 Salvo HID, so you know what kind of hemorrhaging my checkbook has done in the light department.)

 

[NorthWoodsDiver]

Since we are on the topic of lights I thought I would ask if anyone has used these: http://www.leisurepro.com/Catalog.aspx?Op=dtSearch

I dove with a a guy who had 2 of these and I loved them in comparison to my pelican 8D and all my other pelican lights. right now I carry the 8D and a 4AA on everyh dive but their brightness doesnt compair to the brightstar lights that that guy had. I am curious to know how the brightstars compare to other HID lights since they do happen to be considerably cheaper.

 

[cummings66]

I've used lights as shallow as 30 feet, and I've been deeper than 100 feet without them. All in the same body of water.

I've also lost the light at 100 feet and it looked like I was blind, the backup is a poor excuse when you lose your 24 Watt HID but it does work. For a bit you see nothing at all, if you wait a bit things start turning green and you'll see a little but very little sometimes.

I'd say carry a good light and a backup, be prepared to use the backup because mains do fail.

 

[ScubaBeez]

Sluess Pond in Lynn. I'm not concerned about going with my current buddy. I have faith that we know our limitations. I caught a pretty nice cat fish there last year and I wanna see one in HIS environment!