as John has said, to me it is predominately a Naval word. However, it is also used in certain dialects in the UK, for example in Scotland, and in the northeast of England where people would say 'aye' rather than 'yes'. It also reminds me of something I was watching recently where a vote was being held. The story is set in the 18th century in England, and at the end of the voting, a character said something like 'the ayes have it' - meaning that the vote has more people for it rather than against it - if you follow.
I personally never use it in any form of conversations - but I'm from the southeast of England, so that may be why!
I hope this helps,