Brainstorming Shipboard Laser Defense

[OceanWanderer]

Hello,

This is my first post to the forum. I'm an ex-physicist who had a short career with some universities and NASA in my early life, then went on to follow the dollars in the computer industry. Now, I work at sea for a living.

Recently, I was reviewing laws pertaining to shipboard firearms and have decided to work on a non-lethal alternative to the firearms we currently carry aboard our vessel.

Keep in mind that when you are at sea, no help is available aside from your own wits and defenses in the event of piracy or even general armed robbery. You cannot call the "police" and have them come by. You would be long dead by then. Also, there are many countries that have outright bans on firearms with stiff prison sentences if you are found to posses them. Now... on to the question.

I have just finished Googling some of the basics of "dazzle" type weapons currently in production. I have found the following:

*Marines use 532nm, portable hand held lasers as dazzler weapons.
*I have seen dazzlers in 200mW to 800mW ranges.
*I have seen some reference to using infrared lasers instead of visible

In thinking about how to design a system for shipboard defense, it seems it would be quite easy, actually except getting the power and focus of the beam right.

Question: Are there affordable, variable output lasers that go from Class 2 or 3 lasers up to Class4? What are some good quality sources for purchasing such a diode or laser setup?

Specifically for this purpose, I would like to be able to adjust the intensity of the beam from "dazzle" to "something more" in the event of another boat opening fire on us with lethal weapons. In the event we are fired upon, I have no qualms about directing a Class 4 laser directly to their eyes, as they are at that point, trying to kill us. 99% of the time, however, I will just need a "dazzle" effect that doesn't leave lasting damage to the eye, but will render their vision useless for a good 10 or 20 minutes, even in the daytime.

Question: I read about the IR lasers... they seem like the way to go because I don't want the other boat to know I am using such a device, even at night. It would make the laser more effective, because they would keep looking at our boat, without knowing the were getting dazzled. They also couldn't try to take it out with firearms and some pinpointed shooting. What do you think of this idea?

Question: I need to focus (or rather expand) the beam so that it will hit a large section of a boat that is half a mile away or so, max. This means about a meter or so wide. Without going through the math right now, I'll just ask: What power might I need to make this work at that distance, assuming an optically expanded beam?

Ok, I don't know if I'll get a lot of flames on this thread (I hope not), but keep in mind this is a way for our boat to move from a lethal-based defense strategy to a non-lethal one, so it is quite humane compared to the alternative. We currently have several firearms to defend the boat - rifles for distance, short shotguns for close combat aboard the vessel and handguns. Any help on this thread will help us to get rid of those defenses and use a new, non-lethal strategy.

Thank you in advance.

 

[Fish4Fun]

OceanWanderer,

I am CERTAINLY NOT your guy for optics OR lasers, but a precursory look @ the Class 4 laser definition suggests a power density of >500mW/cm^2. If you want an area of 1m^2, this would imply a source power of 10,000 * 0.5W = 5,000W. This is a heavy duty laser by ANY standard. I could certainly completely fail to understand the power density rating of Lasers, so don't take this as any sort of definite answer.

The more general problem with Pirates and non-lethal force is that use of non-lethal force generally presupposes a tactical advantage that I don't think you, as the victim of such an attack, should assume. I would consider armor piercing rounds to the waterline a more appropriate non-lethal response. Obviously the difficulty is separating threats from noncombatant vessels, and I don't have much advice there. The Pirate's have most of the tactical advantages in their favor, and they use that to minimize the decision making process time of their victims. Pirate's tactics include feigning distress, offering help, high closing speed and acting innocent until the moment their trap is sprung. I think the best you can hope under these circumstances as the victim is to respond to the threat with a massive show of firepower.

I applaud your effort to evaluate/devise non-lethal force alternatives to lethal weapons, but I feel that your efforts will place you and your vessel in far more danger.

Fish

 

[berkeman]

Sorry, I have to close this thread -- dangerous activities are not discussed on the PF (see the Rules link at the top of the page).