If in 15 mm, Eureka has a very nice range of American sailors (and great Marines for Midway!). QRF has a pack of German sailors and (I think) command. Or check out Bluemoon's Boxer Rebellion range - lots of sailor figures throughout - though not German but perhaps something readily adaptable (such a search might also work for 28 mm, looking at Boxer ranges. And maybe something in the Bob Murch's Pulp figures ranges?). Peter Pig has some sailor figures in their Sudan range, too.
A lot of nation's sailor figures are fairly interchangeable - the French are perhaps the most noticeable with the little pom-pom on the top of their hats.