46 CFR §154.1830

1. (a)The master shall ensure that a vessel transferring cargo, while fast to a dock or while at anchor in port, displays a warning sign:
   1. (1)At the gangway facing the shore so that the sign may be seen from the shore; and
   2. (2)Facing outboard towards the water so that the sign may be seen from the water.
2. (b)Except as provided in paragraph (e) of this section, each warning sign must have the following words:
   1. (1)Warning.
   2. (2)Dangerous Cargo.
   3. (3)No Visitors.
   4. (4)No Smoking.
   5. (5)No Open Lights.
3. (c)Each letter in the words on the sign must:
   1. (1)Be block style;
   2. (2)Be black on a white background;
   3. (3)Be 7.6 cm (3 in.) high;
   4. (4)Be 5.1 cm (2 in.) wide, except for “M” and “W” which must be 7.6 cm (3 in.) wide, and the letter “I” which may be 1.3 cm ( 1/2 in.) wide; and
   5. (5)Have 1.3 cm ( 1/2 in.) stroke width.
4. (d)The spacing between letters must be:
   1. (1)1.3 cm ( 1/2 in.) between letters of the same word on the sign;
   2. (2)5.1 cm (2 in.) between words;
   3. (3)5.1 cm (2 in.) between lines; and
   4. (4)5.1 cm (2 in.) at the borders of the sign.
5. (e)The words “No Smoking” and “No Open Lights” may be omitted when the cargoes on board a vessel are not flammable.
6. (f)When a vessel carries or transfers vinyl chloride, the warning sign under paragraph (b) of this section must also have the words “Cancer Suspect Agent.”