Department of State
A. A merchant vessel of belligerent nationality may carry an armament and ammunition for the sole purpose of defense without acquiring the character of a ship of war.
B. The presence of an armament and ammunition on board a merchant vessel creates a presumption that the armament is for offensive purposes, but the owners or agents may overcome this presumption by evidence showing that the vessel carries armament solely for defense.
C. Evidence necessary to establish the fact that the armament is solely for defense and will not be used offensively, whether the armament be mounted or stowed below, must be presented in each case independently at an official investigation. The result of the investigation must show conclusively that the armament is not intended for, and will not be used in, offensive operations. Indications that the armament will not be used offensively are:
1. That the caliber of the guns carried does not exceed six inches.2. That the guns and small arms carried are few in number.
3. That no guns are mounted on the forward part of the vessel.
4. That the quantity of ammunition carried is small.
5. That the vessel is manned by its usual crew, and the officers are the same as those on board before war was declared
6. That the vessel intends to and actually does clear for a port lying in its usual trade route, or a port indicating its purpose to continue in the same trade in which it was engaged before war was declared.
7. That the vessel takes on board fuel and supplies sufficient only to carry it to its port of destination, or the same quantity substantially which it has been accustomed to take for a voyage before war was declared.
8. That the cargo of the vessel consists of articles of commerce unsuited for the use of a ship of war in operations against an enemy.
9. That the vessel carries passengers who are as a whole unfitted to enter the military or naval service of the belligerent whose flag the vessel flies, or of any of its allies, and particularly if the passenger list includes women and children.
10. That the speed of the ship is slow.
D. Port authorities, on the arrival in a port of the United States of an armed vessel of belligerent nationality, claiming to be a merchant vessel, should immediately investigate and report to Washington on the foregoing indications as to the intended use of the armament, in order that it may be determined whether the evidence is sufficient to remove the presumption that the vessel is, and should be treated as, a ship of war. Clearance will not be granted until authorized from Washington, and the master will be so informed upon arrival.
E. The conversion of a merchant vessel into a ship of war is a question of fact which is to be established by direct or circumstantial evidence of intention to use the vessel as a ship of war.