OPEN. The situation of a place which is exposed to the wind and sea.
Also, applied in meteorology, to mild weather. Also, open to attack, not
protected. Also, said of any distant visible object.

OPEN HAWSE. When a vessel rides by two anchors, without any cross in her
cables.

OPEN ICE. Fragments of ice sufficiently separate to admit of a ship
forcing or boring through them under sail.

OPENING TRENCHES. The first breaking of ground by besiegers, in order to
carry on their approaches towards a besieged place.

OPEN LIST. One of a ship's books, which contains the whole of the names
of the actual officers and crew, in order to regulate their victualling.
The crew are mustered by the open list.

OPEN LOWER DECKERS, TO. To fire the lower tier of guns. Also said of a
person using violent language.

OPEN ORDER. Any distance ordered to be preserved among ships, exceeding
a cable's length.

OPEN PACK. A body of drift ice, the pieces of which, though very near
each other, do not generally touch. It is opposed to close pack.

OPEN POLICY. Where the amount of the interest of the insured is not
fixed by the policy, but is left to be ascertained by the insured, in
case a loss shall happen.

OPEN ROADSTEAD. A place of hazard, as affording no protection either
from sea or wind.

OPERATIONS. Field movements, whether offensive or defensive.

OPHIUCHUS. One of the ancient constellations, of which the lucida is
_Ras-al-ague_, one of the selected nautical objects at Greenwich. This
asterism is sometimes called _Serpentarius_, its Latin name, instead of
its Greek.

OPINION. An experienced witness, who never saw the ship, yet may legally
prove that from the description of her by another witness she was not
sea-worthy.

OPOSSUM-SHRIMP. A crustacean, so named from its young being carried
about in a sort of pouch for some little time after being hatched; the
_Mysis flexuosus_ of naturalists.

OPPIGNORATION. The pawning of part of the cargo to get money for the
payment of the duty on the remainder.

OPPOSITE TACKS. Making contrary boards. Also, a colloquialism for cross
purposes.

OPPOSITION. A celestial body is said to be in opposition to the sun when
their longitudes differ 180 deg., or half the circumference of the
heavens.

OPTICK. An old term for a magnifying-glass.

ORAGIOUS. An old term for stormy or tempestuous weather:--

"The storme was so outrageous,
And with rumlings oragious,
That I