certainly a greek fire concept with diesel fuel, scuba tank, propane torch ignitor could be prefabbed, and not look like a weapon. paint it white.
This is one of the smartest ideas I've seen. Clearly many who have posted here have no idea how to interpret a threat or how to respond effectively so maybe it's better they don't have the means to inflict harm.
I figure whatever you're cruising in has a tank of gas or diesel. While the threat is still inbound prepare to hose the attackers down with your pre-assembled high pressure assembly and begin launching flairs at them.
Once on board, you better have a weapon. My choice would be a 12 gauge Winchester 1300 shotgun with collapsible stock, 18" barrel and magazine extension, filled with Aguila "Minibuck" shells loaded with #4 buck shot. The shells in the gun should be the only ones on board. If you have to ditch the gun, it's not going to break the bank and there's nothing left on board afterwards. They're made in stainless just for this purpose. The extension will hold enough of these 1 1/2" rounds to either finish off your assailants or force them to make their escape.
Pilferage is one thing, an attack is another. If a group, brandishing weapons is about to board your boat, don't kid yourself, they do
mean you harm. They have to kill you so you don't identify them later.
I like the intense lighting idea too. This should allow you to get the wind at your back as you open the nozzle....
The best way to avoid something like this is to stay alert. Colonel Cooper, father of what is commonly known as the "Modern Technique" of handgun shooting used the following to make his point;
The most important means of surviving a lethal confrontation is, according to Cooper, neither the weapon nor the martial skills. The primary tool is the combat mindset, set forth in "Principles of Personal Defense".
In the chapter on awareness, Cooper presents an adaptation of the Marine Corps system to differentiate states of readiness:
* White - Unaware and unprepared. If attacked in Condition White, the only thing that may save you is the inadequacy or ineptitude of your attacker. When confronted by something nasty, your reaction will probably be "Oh my God! This can't be happening to me."
* Yellow - Relaxed alert. No specific threat situation. Your mindset is that "today could be the day I may have to defend myself." You are simply aware that the world is an unfriendly place and that you are prepared to do something, if necessary. You use your eyes and ears, and realize that "I may have to SHOOT today." You don't have to be armed in this state but if you are armed you should be in Condition Yellow. You should always be in Yellow whenever you are in unfamiliar surroundings or among people you don't know. You can remain in Yellow for long periods, as long as you are able to "Watch your six". (In aviation 12 o'clock refers to the direction in front of the aircraft's nose. Six o'clock is the blind spot behind the pilot.) In Yellow, you are "taking in" surrounding information in a relaxed but alert manner, like a continuous 360 degree radar sweep.
* Orange - Specific alert. Something is not quite right and has gotten your attention. Your radar has picked up a specific alert. You shift your primary focus to determine if there is a threat (but you do not drop your six). Your mindset shifts to "I may have to shoot HIM today." In Condition Orange, you set a mental trigger: "If that goblin does "x", I will need to stop him." Your pistol usually remains holstered in this state. Staying in Orange can be a bit of a mental strain, but you can stay in it for as long as you need to. If the threat proves to be nothing, you shift back to Condition Yellow.
* Red - Condition Red is fight. Your mental trigger has been "tripped" (established back in Condition Orange). You take appropriate action.
Being a pacifist is all well and good when it's only your @$$ on the line. When it involves your family and friends, it a serious lapse of judgment under these circumstances.
You learned how to sail, you should also take the time to learn how to defend yourself and your loved ones.