[fernando]

I wouldn't digest this thing of sailors not being allowed to carry knives without some extra mastication.
The reasoning of, only crew members with an appointed craft be allowed to use them, is perhaps a bit ambiguous.
I am too lazy to browse the books looking for evidence, but in a first thought i would say that, the majority of sailors aboard had one or more crafts to perform; in a way that was the (multi) purpose of professional sailors. Maybe not mechanic jobs like carpentry, or fixing the water pumps, but mending sails, tying ropes and that sort of things. I can not imagine a sailor without a knife; not a folding knife, with a concealing intent, but a tool knife, for a zillion needs inherent from being aboard ship.
If a mutiny had to take place, it was not the knife which played the nuclear key for such decision. Lots of devices found aboard could be used as weapons. Even admiting that only selected artisans could bear knives, this would not be a secure way to prevent mutiny ... either in their own hands or grabed by other men.
Discipline aboard and contention of conflicts passed by other measures.
Besides rank sailors, ships garrison was more diverse, including soldiers and artillery men ... although firearms and gun powder were kept locked and only distributed in case of iminent combat.
Concerning the social status of crew members, ironically were the soldiers that were "drafted" in streets, taverns or prisons and not sailors, as these would have to be more qualified for the job. Soldiers were not so much required to know how to shoot a musket or handle a pike, as sailors had to undoubtedly know how to operate a ship.
In this last one (and half) paragraph i am citing the chroniclers.