I honestly don't know that there'd be any kind of currency on the ship at the moment. Food and shelter and medicines and medical care and, if needed, clothing as well, are all free here for those who are awake. HOWEVER, that does not mean that there wouldn't be an 'underground economy,' likely based on a barter/trade system. Say, for example, someone wanted to play poker - what to use for chips? Candies perhaps, nuts or packages of small sweet food stuffs (like what would be found in an MRE). People might trade for, say, homemade moonshine or wine or beer, or basically whatever your imaginations can pull together.
eta: any "cantina" would probably be unsanctioned and yet very, very popular, I imagine
eta: any "cantina" would probably be unsanctioned and yet very, very popular, I imagine