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°, or half the circumference of the heavens.
OPTICK. An old term for a magnifying-glass.