Let’s start by defining some inconvenient truths:
To think that large, predatory mammals, aggressive reptiles, rabid scavengers, lunatics, drug addicts or thieves can be persuaded not to attack you or steal from you with logic, kindness or pleas for mercy is overtly simplistic and idealistically naive.
It is wrong to think that you will never be victimized by hurtful people because the government of your “civilized country” or state has decided that the responsibility for your self-protection is better left to those more suited to firearms possession and handling then you.
It is impractical and unwise to repel a circling shark with small arms fire from the surface; a wounded shark would most likely draw more sharks. And as we know, sharks are only found in two hemispheres, the northern and the southern!
It is as much a reactionary, fear-based prejudice to “avoid being around anyone that (you) knew was packing heat out of concern that they would actually use it”, as it is to avoid kayaking with homos because they might start doing each other! Fortunately, or unfortunately depending on your perspective, there is more water on this planet than there is tolerance or lack thereof.
I take my personal security with less flippancy and more gravity and activism than “Let us pray for help”.
Packing a first aid kit, folding knife, signal flare or firearm on a kayak all come with implicit responsibility of education of use; each should only be used with careful appropriateness and only when needed. I would be more concerned about the likelihood of being treated by someone with a first aid kit who has hasn’t heard of the Hippocratic Oath than being around a gun owner who hasn’t heard of the four basic rules of gun safety.
Kayaking itself can be dangerous, the purpose of the OP was to help understand how to best mitigate the dangers that can be presented when you are accosted by those who would do you harm, two legged or four. I respect the fact that not everyone wants to own a firearm, much less kayak with one! There are many situations, most in fact, when I would not consider it; like day sailing, surf kayaking and on and on.
But there are also forms of kayaking, such as kayak camping, remote area kayaking and extended touring, when it may be in your best interests to regard your personal safety as your responsibility and not rely on Authorities who are either out of cell phone range, indifferent or otherwise incapable of protecting you from a serious situation in which you could help yourself by considering kayaking with a gun.
Given that, the intent of the OP was to try to refine our choices and their applications.
Synovis, I think you're right on about the poly framed arms, the Ruger LCP or other sub-compact poly gun may be one of the best choices! The problem with my Super Redhwak in it's bandoleer crossdraw holster is that it would be impractical to wear while afloat and too heavy incase of capsize! As a camp gun, there would be no better.
Ranger908, Good to hear from expieriance! Would a semi have an advantage over a pump? For me, either would require a leash to the boat!
Even with the kayak you hunt with a dog for retrival?