Since you asked....
Depends upon what environment your intended use is going to be if different from the environment you use any of your other lasers in.
Is up to you, depending on intended real world use what to get wavelengrh-wise and "waterproof" spec-wise, and what materials the host is needs to be made of. Might be much less costly and easier to get or make a waterproof clear housing to put one of your existing lasers in.
You can guess why nothing is offered already--real dive related equipment is a very specialized business and market and nobody is asking for/demanding underwater lasers. Would guess the money, time , and efforts needed for the necessary Research ,Development,Testing, and Evaluation + marketing for no existing real customer need or market ffor many reasons including FDA kaw, rules, and regualtions reasons probably prohibits it from happening.
Might one day might be a developed item--a serious dive laser if the Chinese military ever has a requirement for same--other sales could then be an offshoot.
For a collection or occasional land use in one thing --use in a fish tank or swimming pool is another --if real underwater dive capable use is needed that is another thing and has to be defined by requirement-.
What kind of water at what depth on a continuous basis and so on. What output, what duty cycle, and so on---Would guess FDA laws, rules and regulations would apply to be legally imported, distributed,, and resold in USA and elsewhere so--- <5mW underwater laser, a less than 1mW version needed elsewhere in the Western world if there is to be any legal sales and Distributors or Dealer reselling.
If not specifically for military specialized use requirement which would be a legal sale by military purchase waiver, it doen't make business sense in making a high power underwater laser.
Even if there were to be no FDA restrictions on hand held lasers for "diving" use other than dive certification perhaps to purchase a dive laser, it would be an uphill battle and tough sell to scuba and dive hobby people as well as diving professionals who have other priorities and an expensive hobby or profession already with equopment to worry about getting and upgrading--would be a tough/very hard to sell.
You should review what was discussed in this thread and then ask Podo the appropriate questions:
http://laserpointerforums.com/f44/world-first-high-power-underwater-handheld-laser-98630.html
There is a section on dive watch depth specifications and what they mean in the real world in the thread also---for dive work, 1/10th of the rated depth is what any of them are good for on a continuous working basis for example as a rule of thumb
You better get Podo to define/give you specs on what the underwater host actually is and is capable of --actual use underwater at what depth
Here is a little bit frpm the above mentioned thread:
"The reasons that there aren't many applications of lasers in an
underwater environment is associated with the way light is transmitted
underwater.
There are two distinct causes for the energy loss of a light signal in seawater:
one is absorption and the other is scattering - 2 separate problems:
A. Most light is absorbed by water -- Water absorbs ultraviolet,
yellow and red and infrared radiation very strongly, so that beams in
these spectral regions cannot be transmitted very far -- meaning that
systems using such lasers are pretty useless. On the other hand, water
(seawater, that is) transmits blue-green light pretty well -- losing
"only" about 5% of its original intensity for every meter it transmits
through water.
B. There are often little specks of dust, tiny animals
(phytoplankton), and tiny plants (photoplankton) in water, and these
reflected a little bit of the light, too, reducing intensity as it passes
through water. This adds to the problems noted above in Item A.
The effect of these two effects is that lasers used underwater have to be
much more powerful than those used in air, where absorption is generally
much lower than in water
Any real underwater "dive" laser host should be a very low tolerance, tight, high precision threaded 904L stainless steel host to prevent premature deterioration due to chloride/salt exposure which is common with most stainless steels or alternatively made from pure Ti or a Ti/Pd alloy host with solid copper internal module/heat sink. Whenever fresh titanium is exposed to the atmosphere or to any environment containing oxygen, it immediately acquires a thin tenacious film of oxide which provides excellent corrosion protection. Salt water is not easy on materials."
Laserbtb offered a hand held laser that was good for 50 meters deep, but highest outputs offered are a 2000mW 445nm model with a 10minutes on/20 seconds off duty cycle and a 520nm with 10 minutes on/ 10 seconds off duty cycle in a 26mm diameter X 19.3cm host, a couple of years ago--maybe you can find a review but I doubt many were ever sold--was not much more than a dangerous water toy.
