[Catfish]

^ This, also including neutral merchants (certainly carrying contraband) into allied convoys. Next, Q-ships. History is still being blurred, and intentionally so.


edit: but i did not mean that a controlling ship had the international right to treat the armed "civilian" vessel as a military ship, treat the crew as military, and sink it (which is bad enough). We know that german U-boat commanders usually did not deliberately target and kill the crew, both wars.

What i mean is, just like in WW1, the arming of civilian merchants (making them military ships, with a military (if small) crew to fire the guns) broke international law.
By this international law a military ship was allowed to stop and search neutral merchant vessels for contraband and then take it as a prize or sink it, and even sink enemy merchants without hailing in certain areas! Complicated enough with british merchants notoriously running under false flags.

This was a "nice" move by british politics, since the sinking of any "neutral" ship could instantly be used for propaganda and blamed on those brutish germans. Truth is, they cheated, and let the outcome be carried on the shoulders of civilian crews. And the propaganda is still strong.

Truth is that even obvious enemy allied merchants were usually stopped, the crew allowed to leave ship, and only then sunk. Also in WW2.
But the armament of merchants, and the running of neutral ships carrying contraband in enemy convoys, made the prize regulation impossible. A U-boat could not risk to surface and stop a surface merchant, when one shot could sink the boat.