For a number of reasons, exonumia (paper and metal) were introduced for circulation on board of a ship. Two of those reasons are:
#1: the company didn't want their (foreign) personnel to spend all of their wages in a port, e.g. N#345624
#2: it was illegal to import or export currency, but the owners of ships with emigrants wanted them to spend their money on board, while being on the ocean, e.g. N#113856
I think this type of exonumia would best be defined as confinement money, but it doesn't fit any of the categories in that section on Numista.
Any suggestions for an existing or new category for this type of exonumia?
Anton