Good post Laird and I agree. I recall your situation when you were being stalked/chased by a bear in the woods. Be good to refresh our memory on that.
A State trooper friend, suggests that any knife carried on the person or in a 'tool bag' should suggest a tool of survival/rescue intent, and not of 'combative' intent.
So you tell the officer that the reason for your having that knife is for reasons of cutting your seat belts, breaking glass to escape your vehicle or render such assistance to some other needy situation.
Because of your kind of work and exposure to all kinds of dangers, I agree you should carry the best knife or combo of knives that also gives you a chance to kill a predatory animal or human 'animal'...
Some of the 'combos' I like are these...

the Tracker, a knife designed by Tom Brown, Jr, a respected tracker and wilderness survival expert. The blade on the tracker is a shorter length (4 ¼”), but the overall length is the same as the KA-BAR. What really sets this knife apart is the design of the blade and edge, which is quite different from most. The mini saw blade on the back, the section on the edge for drawknife usage, and fact that the shape of the blade and handle lend itself easily to chopping, turn this from a survival knife into a survival tool.

SOG SEAL Team Knife:
SOG is one of the top fixed blade knife manufacturers in the world, and their SEAL Team knife is built with extreme abuse in mind. The knife was designed for optimum sharpness, edge retention, tip and blade breaking limits, torsion, salt water immersion, and gas and acetylene torch resistance, plus durability for chopping, hammering, prying, penetration and cutting applications. The blade is 7″ long and .24″ thick, with a partial serration on the edge, and the overall length of the knife is 12.3″. Fans of shorter blades, and non-serrated edges, may find the Field Pup to be more to their liking.