Those of you who have attended the DEMA scuba conventions the past few years have seen small laser pointers for sale. They were toys compared to this baby.  
It uses 2 - 1.5V AA batteries. You can put in the standard pen light batteries or use any of the standard rechargeables. It is 7.5 inches long.
 This can project a sharp, bright beam up to 1/2 mile away. Notice, the green laser we offer here for SCUBA divers is not strong enough to interfere with an airplane. We have produced the strongest laser allowed by federal law that does not require special safety features that would make it way too expensive to produce in a waterproof configuration.  It could be seen by an airplane on a rescue mission at a tremendous distance but would not be bright enough to interfere with the pilot's vision.

If you are a scuba instructor wanting to point out fire coral or a stone fish or a blue ring octopus to your class, you need a laser pointer that they can see underwater even in daylight. This will do it. It not only puts a brilliant green spot on your point of aim, but the actual beam is visible so your students can easily follow your point to the object.

This powerhouse is packed into a 7.5 inch mil-spec heavy duty aluminum case with double O-ring seals to keep it safe.

We have set the power level just below the point where you would need a special license to purchase and use it.

It is also set low enough so as not to injure the sharks.

Here's why this makes all those red lasers seem like toys.
1. To start with, this is an infinitely more powerful beam.  
2. Ask your instructor what color light disappears first under water.  
    It's red.
3. Ask your instructor what color lights are most easily transmitted under water.
     It's blue and green.
4. Ask your instructor what color light is most easily seen by the human eye.
    It's green.
    That's why this is the only underwater laser that is worth carrying.

Use it to point out objects underwater that you can't get near or don't want to get near.
Use it to signal to your dive buddy. You only need to shine it on something in front of him.
That green dot lights up like a star on whatever you point it. Even the beam is visible so it is easy for people to find the dot.  Just follow the beam.

Output Power <5 mW (Class IIIa) Warranty 6 Months
Output Type Constant Wavelength 552 mm
Polarization Linear (50:1) Beam Dia. at Source 1.1 nm
Output Variance 10% after 20 min. Beam Divergence 1 mRad
Dimensions 7.5 in x 1 in Switch Twist cap (double O-ring seal)
Operating Lifetime circa 5,000 hrs Batteries 2 - 1.5 V AA supplied
Range 13,000 feet Class IIIa
Waterproof to 300 feet Beam Color Green

Interesting military use of the green laser
The following article is from the Palm Beach Post Newspaper 19 May 2006
We are reprinting it without comment because we do not intend our laser to be used against people.
However, we felt that our customers would want to be aware of the following information.

U.S. troops to use laser technology
Human rights groups oppose the weapons
BAGHDAD • The U.S. military is deploying a laser device in Iraq that would temporarily blind drivers who fail to heed warnings at checkpoints, in an attempt to stem shootings of innocent Iraqis.
The pilot project would equip thousands of M-4 rifles with the I0 1/2-inch-long weapon, which projects an intense beam of green light to "dazzle" the vision of oncoming drivers.
"I think this is going to make a huge difference in avoiding these confrontations," said Lt. Gen. Peter Chiarelli, the commander in charge of day-to-day operations in Iraq. "I promise you no one — no one —will be able to ignore it."
But so-called tactical laser devices have been controversial in the past.
A protocol to the Geneva Convention bans the use of lasers that cause blindness, and human rights groups have protested previous U.S. attempts to employ such weapons.
The Pentagon has canceled several programs for the stronger "blinding" lasers, in adherence with the Geneva protocol, according to the New York-based Human Rights Watch. But the group has said that even less powerful "dazzling" lasers, similar to the one to be deployed in Iraq, can cause permanent damage.
The military, however, has apparently decided the risks can be minimized through proper training, and are worth taking, to help U.S. troops ward off suicide attacks and to reduce accidental shootings of Iraqi civilians. "I have no doubt," Chiarelli said, "that bullets are less safe."green laser for shark attack