Ideal laser pointer for a long range distress signal at sea

[athomson]

I agree a PLB is first choice. Its just that the sort of thing of sailing nightmares is you go to use it and nothing happens. You then watch planes fly over and ships go by with out them seeing you. The greatland laser is just useful as you say if they are looking for you. I already have a better LED beacon for that. My hope was something noticeable from much further away which was cheaper and just as small. But now I realise those adverts for cheap 500mW lasers are lies and because of the restrictions you mention i can't imagine them getting much cheaper or smaller than they are now. Its a dead end but thanks anyway

 

[athomson]

I just noticed on your first link this "Abby Sunderland attempted a solo circumnavigation of the world in 2010, hoping to become the youngest person ever to have done so. When her boat was disabled in the south Indian Ocean and her satellite phone was not working, a personal locator beacon became her only chance to receive help." This is why you need more than one method, the more the better. If they are all compact items and not too expensive why not take every different type available.

 

[RA_pierce]

compare it to what is used now. Explosive flares that only burn for 30 seconds, dangerous, bulky, expiry dates quite short. Terrible archaic things but still obligatory to carry them in many places depending on type of boat. They wouldn't get to production if only thought of now.

I see your point.

all good thoughts thank you, I agree lithium batteries are sketchy in the cold, had an issue just last week. Are there NiMH batteries similar in size and capacity to 18650s? I can only find AA or C.

Other sizes for NiMH batteries do exist but they can be hard to find. Also, since the voltage per cell is low, you will need more than one.
Eneloops, as far as I know, are only made in the usual sizes (AAA, AA, etc.). While I do like NiMH for reliability, they definitely don't match the energy density of Lithium.

But I think ultimately it will come down to price and maybe size. Now i see that the actually more powerful lasers are quite big and expensive I doubt its such a good idea as it seemed when looking at the bogus claimed powerful pointers.

But what price could you make a 1w red 18650 based waterproof laser for? Perhaps with a beam spreader instead of a plain lens.

Diode: ~$25 USD
Lens: $5-40 USD depending on how fancy you want it (you'll want a glass lens coated for red light)
Driver: $5-30 USD depending on how fancy you want it (a couple AMC7135 regulators will do the trick for cheap but is inefficient)
Heatsink/module: ~$15

Fabricating a host that meets your needs will be the most costly part.
Many will install their assembled laser module in a flashlight body. This offers decent waterproofing if the window is left installed.
However, flashlights most often use clicky switches. I find that in a good quality light, the clicky switches are usually recessed so that accidental activation is not really an issue. It also makes it easy to operate with one hand.

 

[Encap]

I agree a PLB is first choice. Its just that the sort of thing of sailing nightmares is you go to use it and nothing happens. You then watch planes fly over and ships go by with out them seeing you. The greatland laser is just useful as you say if they are looking for you. I already have a better LED beacon for that. My hope was something noticeable from much further away which was cheaper and just as small. But now I realise those adverts for cheap 500mW lasers are lies and because of the restrictions you mention i can't imagine them getting much cheaper or smaller than they are now. Its a dead end but thanks anyway

I just noticed on your first link this "Abby Sunderland attempted a solo circumnavigation of the world in 2010, hoping to become the youngest person ever to have done so. When her boat was disabled in the south Indian Ocean and her satellite phone was not working, a personal locator beacon became her only chance to receive help." This is why you need more than one method, the more the better. If they are all compact items and not too expensive why not take every different type available.

Agree--unfortunately the laser ponter marketplace is dominated by Chinese bandit unscrupulous resellers making false/fraudulent claims just trolling for money.

I understand your thinking--low cost/cheap powerful laser pointer might be a good long distance signaling device if safe, effective, and generally recognized for the purpose none of which is the actual case in real life. Was a noble idea with good purpose.

High output lasers for use as rescue beacons are not going to happen as they would be dangerous to eyesight for both user and target--no laser glasses/goggles, reflections, water, emergency situation fumbling, and handling in general especially by inexperienced and untrained people could just as easily lead to permanent eye damage as an expensive rescue effort of any kind.
At about the same cost or perhaps even lower cost than a high output salt water sea environment waterproof laser, a PLB is a much better choice/way to go 1000X greater chance of provoking an expensive resuce effort given as mentioned " 41 countries participate in the operation and management of Cospas-Sarsat, ready to respond to any one of the over 1 million beacons registered and in use worldwide" and " When activated a PLB transmits your position and your ID to a Rescue Coordination Center via satellite link. Rescue services nearest to your are promptly notified of your emergency and regularly advised of your current location to assist prompt rescue."
Being able to access the only officially recognized worldwide dedicated search and rescue satellite network which is funded by governments and there are NO CHARGES to use, make a lot more sense than fumbling around with a laser of any kind.
I would guess you could set up a system than would continuousy or at small intervals monitor your exact location at all times and provide for distress signal and rescue effort request, as well --- for a price.

I don't see anything but trouble/problems ahead for laser pointers that output >1mW for any purpose in the EU as the are limited generally to 1mW or less by Law apparently and have been deemed to be both dangerous and unsafe and most importantly illegal to sell by EU governing authorities.
EU laws/regulations are what they are:
" Laser Pointer Law in Europe
In short:
Long story short, since February 5, 2014 the European union has decided to ban laserpointers higher than class 2 with maximum 1mW output power. Meaning class 3R (1-5mW),3B(5-500mW) and class 4(500mW+) laser pointers are forbidden to sell and or own in the European union. Source English - NVWA source (dutch)
All laser pointers sold in Europe must comply with the norm: NEN IEC 60825-1:2014 and the general product safety directive under: 2001/95/EC (sources: Source 1 - Source 2) , have a technical file with ROHS and EMC tests and when they comply get a CE marking.

The problem right now in Europe
99% of laser pointer resellers buy them from China and the problem in China is they do not have to comply with European laws so they just place a label on there claiming to be CE compliant and max output 1mW but when tested it is most of the time 10x higher and thus making the CE mark invalid. In Europe when you buy from China you are responsible for complying with the law here in Europe and not the seller in China because the law there has nothing to do with Europe.

So over the last couple of years there has been a spike in laser pointers that are dangerous and unsafe and most importantly illegal to sell.

Why its dangerous to use and sell laser pointers over class 2?
Laser pointers over 1mW are considered dangerous because when for example a class 4 laser hits the pupil in your eye, you will become permanently blind. In June, 2018 A boy in Greece has permanent eye damage by shining into his own eyes. Besides eye damage class 3 and 4 laser pointers can burn your skin within 15meters! Imagine if anyone could buy these without restrictions so the 2014 ban is a life saver for many but unfortunately there are still webshops selling illegal laser pointers higher than class 2. Its our mission to stop them and educate them about the law in Europe."
From: https://www.rapexlasers.eu/laserpointers/law

 

[WizardG]

Build an LED emergency strobe using a Luminus 90 series LED or one of those 100W multi-die packages. 30ish WATTS of optical output and omnidirectional so you don't have to notice the distant plane or boat before they notice you.

Those parts are very high power but with 1ms pulses every second the duty cycle is low enough that no heatsinking will be needed and the battery life should be very good.