POP lite F2 Cree Q5 100-Lumen Diving LED Flashlight (4*AA)

Pros: Great backup light for scuba diving. Corrosion problems of the magnet in the switch with original model are solved by the manufacturer by filling the switch with epoxy resin. If used as a backup, the 4 included AA batteries will last a lifetime.
The beam is very focused with little spill, making the light ideal for underwater communication and reading your instruments.

Cons: Replacement o-rings are hard to obtain.

Other: Great backup light for the recreational scuba diver.

Pros: Very very very cheap diving flashlight with enough lumens for a great backup light.

Cons: The only con I can see is tint of a light, it's too white(with a pinch of blue).
That's not good color for diving flashlight, yellow is more suitable because of lower rate of back-scattering.

Other: Cheapest diving light on market, and by far not the weakest.

Pros: This is a good dive torch.
I use it for Caving /Mine exploration mounted on the side of a helmet.
Good magnetic switch the torch colour is also very good makes finding it easy.
The use of AA's is good a common easily avalible size you can use rechargable nimh as well.
Good double "o" ring seal reliable current limmit resistor fitted(which can be modified with a driver replacement).

Cons: Cons,
I'm worried about cross threading but have lubricated the threads to make assembly/dissasembly easier.
The resistor, far better with a driver fitted.

Other: Cheaper than some similar dive torches which is a big plus point.
It's a light weight torch as well.
Tight bright beam.

Pros: Good build quality.
Enough lumens.
Very narrow beam angle.

Cons: Ony con so far is tint of the emitter.
It's to blue-ish, and that is not the best color for diving torch due to higher amount of back-scattering.

Other: Cheap and really great light, it's suitable as a backup light during night diving or as a primary during day. Small and powerful light to always have it in your jet-bag.
It's a must buy product due to it's low price.

Pros: Inexpensive, good quality, nice tight beam with a lot of throw (if that's what you want).
The quality is as good or better than my numerous Underwater Kinectics lights.

Cons: My biggest concern is the o-ring. Someone said it has 'double o-rings' - that's not correct. It has a custom gasket and a silicone o-ring. The gasket, which appears to be buna, is obviously not available should it need to be replaced. From a close look at the gasket, the sealing surface appears to be slightly distorted (water-tight?).
The o-ring is silicone - silicone o-rings are used in static applications like camera housings - not dynamic applications like dive lights. One of the reasons for that is that silicone tears more readily than buna.
After removing and reattaching the head several times, my silicone o-ring distorted and stuck out from the groove that it is supposed to nest in. If you don't push it back into the groove, you might end up nicking it. I'm planning to replace it with a buna o-ring -- if I can find the size.
Someone mentioned lubricating the threads. If you decide to do that - be careful - silicone grease is not appropriate for use around silicone elastomers.

Other: I bought this for OW recreational diving. Just received it, haven't dove with it yet.
Best uses:
Looking into creviches on day dives. Back-up for night dives.
It has a nice tight beam with good throw. The beam is too tight to be used as a night dive primary light.

Pros: Nicely built, sturdy plastic chassis with easy operating on/off switch. Colour of the body is screaming yellow, you simply can't lose it. Comfortably sits in hand. Included batteries still last eventhough I own it for more than 6 months. Never used it exessively though. As quantity of light is concerned....boy, this one could roast a chicken. Really!

Cons: There are two dozens of tiny holes around the reflector rim and when you switch it on it really pokes your eyes. In deep dark it could pose a problem. So, consequently, I covered it with rubber band and it's OK now. Could be priced less...

Other: Great torch for the money. Lightweight and effective.

Pros: Very bright. Good build quality and bright colour (it's your fault if you lose it).
The magnetic swith is a nice touch in order to minimize the risk of floodings.

Cons: The light beam is a little too narrow. It would be nice if it was wider in order to use as primary lighting in night dives, but it's OK for looking into small caves.
First use was a 20m dive. I didn't put any grease in the O-ring and a little water got into the light. I disasembled it, let it dry, then clean, put a little silicone grease and no more leaks.

Other: If you don't have one, buy one.

Pros: This flashlight is incredibly powerful to use only 4 AA batteries. The battery life is also something of note. Lightweight and durable. The body itself is constructed in one piece, being the only thread connecting point of the lid. The magnetic switch is impeccable, it´s easy to activate with a single finger.

Cons: Absolutely none

Other: The case, in addition to the flashlight includes 4 AA batteries and a set replacement o rings. I tried this lantern in the pool at my club, and even in low light (a little dirty water) looked at the other end of the pool (approximately 20 meters) I hope to use it in my next dives.

Pros: Nice small light for a very low price.
Electronics are very simple but that is a pro if you want to mod it.
As a backup light or small light for holidays it is very usefull.

Cons: The O-ring is the main down side. This is silicon and has to be replaced by a stronger O-ring as silicon is quite weak and can tear easily.

Other: Nice light that is very usefull as is.
But many possibilities for mods.

Pros: - Led
- Easy switch, no hole in the body as magnet activated.
This one has only one mode, the LION one has two mode (usb rechargeable , F6 version)
Have been tested several times at 30m
I used as spare light or to gives to someone having no lamp yet (for one dive)

Cons: As other mentioned, small hole around the reflector gives side light (90° of body).

Other: Very good buy, one of the best :-), sold 2 or 3 times the price of DX in belgium. So cheap i have used it as a gift for a friend diver, he was really surprised ;-).