🤣 "Matey" is actually quite common in a few parts of the English-speaking world. Even among landlubbers lol. Although I've also never seen it written as "M80". It used to be "m8" for "mate" back in Nokia days to save space.
Some people even use it as a sort of catch-all informal way to refer semi-affectionately to an unnamed third person. "Oi, matey here would like a word with you." You probably won't hear it down the old boys' posh cigar club though tbf, old chap.
Cu l8r m8.