Dangerous knives in NY are best classifed one of two ways: design and intent. Some knives are deemed to be weapons by design : tanto blades, double edged blades, kriss and some others. While some of these maybe legal to possess at home, they are not legal to carry or have readily accessible in a car while transporting. The other issue is intent. In NYS you may not carry any item designed for use as a weapon. Your statement that you are carrying it as a weapon ( including self defense) makes it a dangerous item. Your question about a Bowie style knife does not have an absolute answer. I don't consider it a weapon by design, but others might, and many states list the term Bowie knife as a weapon ( NY does not do so by name). This is the over all problem with knives in general as alot is open to the understanding and training of the officer you are dealing with. I can almost bet that if you show any knife to five different officers you will get five different statements as to wheter or not it is legal.
I will offer a few examples of this: I posted this a few years back: I was at the Broadway Mall with my son and two plain cloths officers stopped three teens and found one in possession of a flickable locking knife. The one officer quickly stated it was a gravity knife while the other pulled him aside to question my he thought it was illegal. The kid ended up in the back seat in handcuffs. It was clear the two officers had differing thoughts but the teen was still taken away. I can also tell you of an arrest by the Queens North Task Force of the NYPD awhile back for a group of four men in a car that had an open box of steak knives in the car. When the officer asked why they had the open box of steak knives, the men honestly asnwered they had been fearlful of an attack by another group of men, and were carrying them for self defense- they were all arretsed. So you see it is hard to make you feel that you are fully legal in carry a Bowie style knife in NY, but I feel if you are engaged in a camping or sporting activity you will most likely be fine out side of NYC.....I wish it was as clear as having a pistol permit or not, but sadly it isn't.