Though I have never been to the Bahamas, I know that they have a 15 cents coin, and I wonder just how useful it is. I doubt that I would find it useful, if I lived there. However, I notice that the USSR had a 15 kopecks coin, and this may have been copied by various countries of the communist bloc - I don't know. I suppose that it is no more unusual than the half crown in the UK (2½ shillings).
The USSR also had a 3 kopecks coin. It does not seem very useful to me, in a decimal system. We had a threepence coin in the UK, before decimalisation, but there were 12 pence in a shilling and a threepence therefore represented a quarter shilling, which made sense. Again, I think that the concept of a subunit of 3 was copied by some countries in the communist bloc.