What to look for in a flash light

[VR78]

I have to respectfully disagree with @tbone1004 with regard to the Focus. I have never seen the 2.0 in flesh but been using the 1.0 for a more than a year now and teamed up with folks using various premium lights from various manufacturers (Thor, Halcyon HID, LM, UWLD, DiveRite, Green Force etc). My experience has been that the 1.0 has outperformed each and every one of these by a considerable margin. There are two reasons for this. Firstly, this is the most focused (pardon the pun) light of them all, with I think a 4 degree spot beam angle. As a result, the spot remains very tight over considerable distances allowing for easier communication. Secondly, in low visibility conditions the light cuts through the particles much more effectively than most others. Where many lights produce just a spherical halo, the 1.0 still gives a nice, easily perceptible beam. As a communication and team awareness device, I think 1.0 is as close to perfect as it gets.

Granted, there are downsides to the Focus too. The handle, while absolutely awesome and easily adjustable, is not really suitable for scootering. They have a replacement Goodman handle (the "Explorer") with a proper thumb loop - but I decided to keep the original one for better flexibility in adjustment, and more importantly for more protection during traveling etc. as the handle folds in to protect the light head. The second downside is the beam adjustment mechanism which I'm sure adds quite a bit to the cost of the light. Over >150 dives I have not once had the need to use the wider beam.

With a lithium battery and <100 Wh surely the Focus can fly, both in cabin and checked luggage (see below).

Capture00

• VR78
• Jul 18, 2017

Capture001

• VR78
• Jul 18, 2017

 

[tbone1004]

@VR78 it all depends on what you are looking for. The Focus is not a superior light in terms of cost:features etc. to others on that list. It is very expensive for what it is. The very tight beam angle is also very restricting in many parts of the world where you actually want to see what you're diving in. I.e. it's completely inadequate in large caves because you can see a very small portion of it. I want to see the cave. My UWLD35 which has a very wide beam angle in comparison causes the entire cave to dance when you start to signal with it.
My team uses 4 light signals, and that's it
OK-big lazy circles that have a hard stop at the bottom. Pretty easy, don't need a laser pointed for that one
Attention-flat lines with a hard stop on the outside *i.e. on the left if signaled by left hand, right if on right*, or on the bottom if signalling vertically. Again, pretty easy.
Trouble-rapid movement of light-same thing here, no laser pointed required
Look/go in that direction-usually not a signal we use unless on scooters, but it's basically "OK" around the intersection and then point the light down that direction. Diver in the back will acknowledge or flash attention if it's a wrong turn.
With as bright as the lights are, they cast shadows on the diver in front of you. We use this to make sure our buddies are back there. If you're in the back, you'll often see the lead diver put his light straight down which usually means he's looking for the shadow from your light. Pretty easy to spot with 3500 lumens coming forward, not so much with 800, very easy with a nice even beam spread, not so easy with a laser pointer.

Other than that, there isn't a whole lot else to talk about with a light. I know there are other signals, but we choose not to use them. The wide beam can contribute to a lot of backscatter, but the LD-15 has a 6* beam angle that is more than adequate for signalling.

That said, while the tight beam angle is nice in certain scenarios, and I tend to agree that as a communication device, the 4* beam angle is better in general, but I use a light to see things, not to talk to my buddies. If I want to talk to them, I have wetnotes and hand signals. Flash attention, they stop, look at you, then you converse with your hands. Much easier and on a dpv in a cave, safer to talk while stopped, then while moving.

If the battery packs don't have UN38.3 certification, they can't fly, no matter how small they are. Will you get caught? Who knows, up to you, but it's a risk I'm not willing to take

 

[VR78]

If the battery packs don't have UN38.3 certification, they can't fly, no matter how small they are. Will you get caught? Who knows, up to you, but it's a risk I'm not willing to take

@tbone1004 Are you sure? I only found the 38.3 requirement under cargo/shipping rules, not passenger luggage transportation. Can you point me to the relevant document?

I like your definition of a focused light as "laser pointer". I guess I do prefer this kind, most likely because of the local conditions: more often than not only 2-3 ft visibility because of the algae, and very little or no ambient light.

 

[BDSC]

This is about the best article I have read on flying with battery packs. After just quickly looking at it, I'm not sure what tbone said about the UN38.3 certification is correct but I didn't read the entire article word for word.

Transporting Lithium Batteries

This is even better:

https://www.faa.gov/about/office_or...fo/media/Airline_passengers_and_batteries.pdf

Doesn't say anything about needing a UN38.3 cert.

 

[VR78]

Doesn't say anything about needing a UN38.3 cert.

Indeed the second document doesn't. In the first one there is a reference to 38.3 testing but specifically for shipping:

Q: Must lithium-ion batteries be tested for shipment?
A: Yes, all Li-ion must be tested according to UN 38.3. Exceptions are made for prototypes and for testing purposes. Refer to CFR 49 173.185 (e) for requirements regarding the shipment of cells or batteries that have not been tested to the requirements of UN 38.3.

 

[BDSC]

For the average person carrying on batteries like we do as divers, UN38.3 is not an issue. I think you are right, it's all about shipping.

 

[tbone1004]

https://www.faa.gov/about/office_or..._Materials_Carried_by_Passengers_and_Crew.pdf

if you read the CFR which is linked above it says the following

Each installed or spare lithium battery must be of a type proven to meet the requirements of each test in the UN Manual of Tests and Criteria, Part III, Subsection 38.3

 

[VR78]

Each installed or spare lithium battery must be of a type proven to meet the requirements of each test in the UN Manual of Tests and Criteria, Part III, Subsection 38.3

Well yikes.

Silver lining:

Allowed:  Diving lamps and other battery-operated extreme heat producing equipment in carry-on or checked baggage. Energy source or a heat producing component must be disconnected or removed.

 

[tbone1004]

Well yikes.

Silver lining:

Allowed:  Diving lamps and other battery-operated extreme heat producing equipment in carry-on or checked baggage. Energy source or a heat producing component must be disconnected or removed.

doesn't remove them from the bit quoted above, but that's just saying they have to be disconnected during travel which is fair enough.

 

[wheeledgoat]

It's "only" 1000lum, but great as a rec primary so long as you're not doing night or cave diving. I use a cross-section cut of a bicycle innertube to keep it firmly attached to my bc shoulder strap, easily within reach but out of the way. It's a twist-on, though, so if you're somebody that can't et along with those, nevermind

SecurityIng Waterproof 1000 Lumens XM-L2 LED Diving Flashlight UnderWater 150 Meters Depth Bright LED Lighting Lamp Dive Lights Torch for Diving https://www.amazon.com/dp/B00CRAARMC/ref=cm_sw_r_cp_apa_Cn1BzbQJWERY0