A laser for diving needed

[Yavox]

I am looking for a laser suitable for pointing at various things underwater when diving. My requirements are:

- submersible to 100m
- effective range about 40m underwater
- any color that works (I don't know what would be best suited to this kind of use - green? blue?)
- as bright as it can be without the risk of damaging the eyes of other divers
- powered by LiONs (like 18650s) would be nice

Any suggestions?

 

[Raccoon]

- as bright as it can be without the risk of damaging the eyes of other divers

Well, right off the bat, that disqualifies most all lasers.

I think to really answer your question, we need to know what your _real_ priorities are. For instance; Are you purely looking for just any submersible laser that can be used to point at objects? Or are you looking for "a really cool bright laser that can shoot underwater beams of God for miles", and really impress your friends?

Right now, you can go to the Dollar Store and buy a cheap red laser that will do exactly what you NEED, safely.

If you want the magical trident of the sea gods, then you're talking a $200~$2000 laser, probably green or blue should work equally well. Cost for Power, right now the 445nm blue is the cheapest, but also non-existent until anyone actually gets their orders shipped. Very dangerous power levels too.

 

[DM51]

Red would be no good for objects >15 feet away.

 

[Yavox]

Well, right off the bat, that disqualifies most all lasers.

I think to really answer your question, we need to know what your _real_ priorities are. For instance; Are you purely looking for just any submersible laser that can be used to point at objects? Or are you looking for "a really cool bright laser that can shoot underwater beams of God for miles", and really impress your friends?

I am looking for a laser which will be mainly used to point at objects. I also want the beam to be visible underwater easily in case I need to draw attention of somebody diving a few meters in front of me. I think the beam should be green or blue.

I don't want to impress my friends, scare the sharks, pop baloons, pierce oxygen tanks or anythink like this - the power could be a way beyond 5mW but still within some reasonable and practical limit - just in case somebody gets hit into an eye for a fraction of a second.

 

[alpg88]

blue would be bad choice as well, you want green, my 130mv blue laser is a lot harder to see (the beam) than 50mv green, also when i shine them into water, blue laser beam looks 2x as thick, but a lot dimmer, also the point itself is a lot brighter with green laser. in the water they loose a lot. so you need at least 50mv green , or more. as for safety, it is all in your hands, be careful where you point it.

 

[arek98]

Looks like here is some interesting info. May be worth contacting them.

 

[Raccoon]

Personally, I'd look for a flashlight + laser combo. The less toys you bring with you, the more hands you have free.

 

[Ken_McE]

Colors in the blue to green range should have the best penetration. Do you need this unit to be shark mountable?

 

[DM51]

Do you need this unit to be shark mountable?

Sharks are quite dangerous enough already without mounting lasers on them, lol.

 

[jspeybro]

if you're going to hold it in your hands, don't go above 5mW or you'll have risk to damage the eyes of your buddies. You'll want a class II (or 2) laser if you want to keep it safe.

other than that, I'm not really sure a tiny laser beam is going to draw much attention.
to try the concept, get some cheap laser pointer and build it in an old backup lamp and see if this is actually usable.

If you want to know more about laser safety, have a look at CDRH 1040.10 norm or IEC 60825-1 norm.