This is a question that has plagued me for years. All the services have enlisted rank insignia on both sleeves, except the float boys who wear it only on the left sleeve. The navy, being as deeply rooted in tradition as any of them, and having reasons for everything involving their uniforms (Only the navy could have a legitimate excuse for wearing bellbottoms) would, I’m sure, have some sort of reasoning for this. I’ve asked every sailor I’ve ever known, did countless searches and read many books trying to find out the reason but I’ve never gotten an answer. Even the sailors, when asked, always got a glazed look in their eyes as if they never realized it up until then. I’m sure many a person yelling at another from the right side to get a haircut got reamed when the the hippie turned around to show that his left sleeve had more stripes. Anybody have an answer or a good guess? Any good navy jokes in lieu of an answer are appreciated as well:)
the navy only has rank on one sleeve cuz they’re wierd like that. they don’t even have ice any more because the guy with the recipe retired
My boyfriend was in the Navy, and this was his response, which he prefaces with: “I THINK this is the right answer.”
Apparently you have to be able to distinguish between “line officers” and other types of officers. Line officers are the guys who get to be in charge of the boat when they’re the highest ranking officer present. Other officers might be present but if they’re not line officers they don’t get to be in charge.
Scenario: There’s a fire which kills off the top guys who would normally be in the chain of command. There are two guys left. Officer A outranks Officer B, but Officer B is a line officer, whereas Officer A is not. Officer B gets to be in charge of the boat.
The boyfriend informs me that once upon a time, the Navy had a similar system for enlisted men too, but has since dropped it. However, when this system was in place, you had to be able to tell with a glance at the insignia whether someone was in the line of command or not. So if you were in the line, you had your insignia on one side. If you weren’t, you had it on the other. So for example, if you were a Bosun’s Mate third class you would have the insignia on, say, the right side, whereas a Musician first class would have his insignia on the left side. (The ship’s band not being in the chain of command.)
This page actually has a history of the rating badges: http://www.history.navy.mil/faqs/faq78-5.htm
Relevant quotes:
1866: "The regulations specified that petty officers of the starboard watch were to wear rating badges on their right sleeves. The left sleeve was to be used for those on the port watch. "
1913: “Ratings badges were no longer worn on the sleeves corresponding to assigned watches. Right arm rates were to signify men of the Seamen Branch; left arm rates were to be used by personnel of the Artificer Branch, Engine Room Force, and all other petty officers.”
1949: “Right arm rates were disestablished 2 April 1949. All rating badges were to be worn on the left sleeve with the eagle facing to the right.”
So it sounds like there used to be a logic to which sleeve that insignia was on. Over time they decided this was not needed, so they made everyone use the left. I suppose they could have changed it so everyone wore it on both – but then everyone would have had to sew on a new patch.
And I thought it had something do with runny noses. As an Army vet, I couldn’t resist 
Outstanding! Thanks a lot! That’s the first answer I’ve ever found that actually makes any sense. It’s still pretty stupid looking (I’m a nut for symetry) but when you are in bellbottoms, the trimmings really don’t matter 
A dogfaced dog doc? Pretty cool