The correct answer is C) stadimeter. A stadimeter is a hand-held instrument used to measure the distance between the ship and an object, such as another vessel or a landmark. This is done by aligning the object with the markings on the stadimeter and using the distance scale to determine the range. This type of instrument is commonly used in maritime navigation and is a required piece of equipment for Coast Guard Captain's License examinations. The other options are incorrect because: A) a vernier is a precision measurement tool, B) a psychrometer measures air temperature and humidity, and D) a hygrometer also measures humidity, but none of these are used to measure distances between the ship and other objects.