If I was a pirate and had a boatload of AK-47’s & RPG’s at my disposal, I don’t think an inaccurate flare would slow me down much. Instead, I’d lay down suppressing fire and lob 1 RPG on the deck. While the crew is scrambling for cover, out come the boarding ladders and game over.[/QUOTE]
The tools used for defense of a ship in HRW (High Risk Waters) can be divided into two categories, lethal and non-lethal. Like it or not, there is a requirement in some cases to warn small craft before the use of deadly force can be authorized. Using light weapons such as AR-15 for warning shots is problematic for a number of reasons. Some limitations are, short range, the shots can not be heard above the noise of the boat’'s engine, the spray from the round is not conspicuous during the day and can not be seen at night. Another limitation with using warning shot is that they can be lethal as in the case of the Enrica Lexie.
In some case there is a requirement to warn small craft using non-lethal tools only.
Your question is regarding the effectiveness of the LRAD. My answer is that they have not proven to be an effective deterrent. As far as the use of an LRAD for warning, I think flares are a better tool as they are cheap, light and portable and they can easily seen both day and night.
If the situation calls for the use of deadly force then flares are the wrong choice if other, more powerful tools are available .
If you are working on a school project likely you already have read the U.S Coast Guard’s guidance on the use of force for self-defense. If not it is PSA (3-09) and can be found here.