Neutral ship (plane) marking 1939

[Kari Lumppio]

Hello Folks!

In photos (1939-40 era mainly) one can often see neutral country ships with enormous flags painted on their sides. Also the name of the country is also painted in huge letters on the ships' sides.

I believe these markings were introduced September 1939 (or even earlier?) when WW2 broke out. Neutral country ships had to be marked clearly to avoid being shot at.

Similar markings can be seen also on some of the airliners of the era. I believe I have seen such markings (National flags on wing tips and tail plus country name painted on fuselage) on Finnish, Swedish, Danish and Estonian planes. Does anyone know if Dutch, Belgian, Norwegian, Latvian, Lithuanian etc airlines took the neutrality markings in use?

I believe that the markings were regulated by some international act or law. All of my searches in internet for such have been in vain up to date. Perhaps UK naval certification issuer (which was??) or somesuch has details of these markings?

What I am most interested in is if the markings were recommendation only or a requirement when entering a war/blockade zone? And secondly what the markings were supposed to be? There seems to have been some variaton in the application (reading direction of the country names on fuselage for example).

Any and all tips where I could find more information of the issue of the neutrality markings are welcomed.


Thanking in advance,
Kari