no, once you have chosen a nation for your sailors it will be permanent, the only way you
can do is to
1) make a new bo
or
2) make a ticket to tnf that you either (if your new to the game) that you accidentally
pick a wrong nation for your bo, but don't get high hopes cause its will be .1 % they will
consider

http://trainworld.us/NF2/English/index.html

go there and see all nations/guns/airplanes and dont forget to read the guides for
begginers.This game can be real hell for new people. 3 hours in reading guides can save
you 1-2 monts grinding for nothing.

You can not.

no, once you have chosen a nation for your sailors it will be permanent, the only way you
can do is to
1) make a new bo
or
2) make a ticket to tnf that you either (if your new to the game) that you accidentally
pick a wrong nation for your bo, but don't get high hopes cause its will be .1 % they will
consider