Hi Neil,
You don’t mention scale which would help, but I find that the larger the scale the more difficult to find a selection of figures. George Turner did a good range in resin at different scales up to 1:12. I myself am still lookin for some suitable figures for my motor yacht in 1:16.
Garden railways were a good source at about 1:25 and 1:19 but they seem to have dried up too- or are rather whimsical! Tamiya were also a good source for 1:32 conversions as were Scalextric figures- not sure if the latter are still available. There seems to be no shortage of lifeboat figures.
Good luck and let us know how you get on.
Ian