25. Complete the following sentences using one of the answer choices given below each question.

1. I ………………………….. smoke, but now I have stopped.

a) used to

b) use to

c) am used to

2. That auditorium …………………………. be a cinema.

a) use to

b) used to

c) was used to

3. I ………………………. like opera, but now I don’t.

a) used to

b) use to

c) am used to

4. I ………………………… like western music, but now I do.

a) didn’t use to

b) didn’t used to

c) use not to

5. I always ……………………….. be afraid of the dark.

a) use to

b) used to

c) was used to

6. I ……………………….. drive a big car.

a) didn’t use to

b) wasn’t used to

c) didn’t used to

7. I have lived in a big city for ten years, so I ……………………… the noise.

a) am used to

b) used to

c) am use to

8. It took me a long time to …………………………. living in the country.

a) get use to

b) get used to

c) used to

23. Unit 11. Navigating a ship. Aids to navigation

1. Navigating a ship.

The word "navigate" comes from the Latin navis, meaning "ship," and agere, meaning "to move or direct." The Latin word navis comes from the ancient Greek nafs, meaning "ship".

The officers and crew of a ship work as a team to see that the passengers, the cargo, and the ship itself arrive at their destination safely and on time. To sail a ship long distances across open water requires great skill and experience. A change in the wind's strength or direction, or the force of the waves and currents, can put a ship off course. A ship's officers use equipment and methods developed hundreds of years ago - as well as modern devices - to tell where their ship is at all times.

There are four basic methods of navigation at sea: Piloting, Dead Reckoning, Electronic Navigation, and Celestial Navigation.

In piloting, the navigator directs a vessel from one place to another by observing such landmarks on the Earth's surface as lighthouses, beacons, buoys, and prominent rocks and cliffs, and by measurements, called soundings, of water depths.

In dead reckoning, the navigator determines a ship's position by keeping a careful account, or reckoning, of the distance and direction of travel from a known position called the point of departure. In electronic navigation, the navigator determines a ship's position with the aid of such devices as radar and others. These instruments variously make use of the directional properties of radio waves, of differences in the times of arrival of radio signals sent simultaneously from different locations, or occasionally of the difference in speed between radio waves and sound waves.

In celestial navigation, the navigator finds a ship's position by observing the sun, moon, planets, and stars.

While in sight of land, the navigator uses the techniques of coastal navigation to find his position. Navigation in coastal waters is known as pilotage. At regular intervals the officer on watch takes observations of conspicuous landmarks, such as lighthouse or a church spire, using the ship’s compass and a sextant.

Entering and leaving port

The area between the port and the open sea often contains hazards and currents that a visiting Captain could not be expected to know. Special shore-based mariners called pilots are hired for their local knowledge to guide ships through this area. They are licensed by the local port authority, and employed by the visiting ships.

The harbour pilot guides the ship into the harbour or out into open water. The harbour pilot must know every channel, turn, sand bar, or other obstacle that could endanger the vessel. After a ship reaches open sea, a small boat comes out and carries the pilot back to port. The ship officers then navigate the vessel to its destination.

Once they have navigated out of the port, they have to be "dropped"; in poor weather, this is a real exercise in ship handling and seamanship. The ship is stopped with the wind at one bow. This creates a lee (patch of smooth weather) on the other side of the ship.

The pilot's boat can then safely come alongside the foot of the ladder by which the pilot disembarks. In very bad weather it may be impossible to create a good enough lee for the pilot to disembark in which case the poor pilot finds himself sailing on to the next port without any luggage!

When a large ship leaves port, three or four small tugboats pull it from the pier into the harbour. A docking pilot directs the tugs and the ship until the vessel clears the pier and is underway in the harbour. The tugs then leave the ship and the docking pilot turns the vessel over to a harbour pilot. Every merchant ship enters and leaves port with a local harbour pilot aboard.

On the bridge, the navigator, usually the second mate, uses various equipment to locate the ship's position. As sailors have done for thousands of years, the navigator checks the position by observing the sun, moon, planets, and stars. For hundreds of years, the most important navigation devices have included a compass to tell direction, a chronometer to tell the exact time and help determine a ship's longitude, and a sextant to calculate a ship's latitude by measuring the angle of the sun or of a star above the horizon.

Modern ships also have highly accurate electronic navigation equipment. Many ships have devices for determining their position through radio signals. These signals are sent out continuously by special transmitting stations along the coasts of busy trade routes to establish position. One such system is called Loran, for long range navigation. With Loran, an accurate position can be obtained in bad weather and poor visibility without a compass, chronometer, or sextant. The echo sounder sends a radio signal from the bottom of the ship to the seabed, from which it is reflected. Many ships also can determine their position by signals that are transmitted from orbiting satellites. The principal function of the system is to acquire automatically the signal of any navigational satellite that comes within range, and to pass the data received to the computer.

Modern ships also carry radar. At night and in bad weather, a ship's radar can spot icebergs, rocks, and other vessels in time to prevent a collision. One should bear in mind that the radar may not detect small vessels, ice, and other floating objects such as containers. Some modern ships also have an automatic pilot, which, after a ship has been set on course, holds it there. This device is linked to a gyrocompass, which determines direction, and it operates the rudder automatically.

Except electronic aids to navigation all ships should carry adequate and up-to-date official nautical charts, sailing directions, lists of lights, notices to mariners, tide tables and all other nautical publications necessary for the voyage.

Official nautical charts can be either paper or electronic charts, produced by a national hydrographic office. Unlike paper charts, electronic charts need to be displayed on an electronic chart display system.

In spite of all these remarkable devices, navigators still also use the tried-and-true compass, chronometer, and sextant.

The speed of a vessel is given in knots. The term “knots” means velocity in nautical miles per hour.

An instrument for measuring the speed of a ship through water is called a ship's, or maritime, log.

Written accounts of voyages are kept in logbooks, or logs. Entries commonly include such navigational data as the ship's course, speed, and distance travelled as well as weather information. Carefully prepared logbooks may be sources for data used in preparing navigational charts.

The unit of distance used by navigators is the nautical mile. One Nautical Mile has an average length, on the Earth's surface, of 6080 feet (1852 meters).

For short distances the cable, or one-tenth of a nautical mile is used. For measuring the depth of the sea, the fathom (6 feet) is the nautical unit of length.

The human navigator is becoming more and more a manager of computer systems; however, there is no substitute for human judgment to deal with the occasional unexpected situation.