Module 11: The Cruise Ship Sector. Destination #3

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1 Module 11: The Cruise Ship Sector Destination #3 Cruise Destinations Welcome to your third destination. Use the following resource article to learn about the different oceans and time zones. Seen from space, our planet's surface appears to be dominated by the color blue. The Earth appears blue because the oceans dominate the surface. Oceans cover approximately 70.8% or 361 million square kilometers (139 million square miles) of Earth's surface. The average depth of our oceans is about 3.8 kilometers (2.4 miles). Maximum depths can exceed 10 kilometers (6.2 miles) in a number of areas known as ocean trenches. The oceans contain 97% of our planet's available water. Below is a table showing the surface area of our planet covered by oceans and continents: Surface % of Earth's Total Surface Area Area Square Kilometers Area Square Miles Earth's Surface Area Covered by Land 29.2% 148,940,000 57,491,000 Earth's Surface Area Covered by Water 70.8% 361,132, ,397,000 Pacific Ocean 30.5% 155,557,000 60,045,000 Atlantic Ocean 20.8% 76,762,000 29,630,000 Indian Ocean 14.4% 68,556,000 26,463,000 Southern Ocean 4.0% 20,327,000 7,846,000 Arctic Ocean 2.8% 14,056,000 5,426,000 The spatial distribution of ocean regions and continents is unevenly arranged across the Earth's surface. In the Northern Hemisphere, the ratio of land to ocean is about 1 to 1.5. The ratio of land to ocean in the Southern Hemisphere is 1 to 4. This greater abundance of ocean surface has some fascinating effects on the environment of the southern half of our planet. For example, climate of Southern Hemisphere locations is often more moderate when compared to similar places in the Northern Hemisphere. This fact is primarily due to the presence of large amounts of heat energy stored in the oceans.

2 The oceans of the world are divided into five regions: Atlantic Ocean Arctic Ocean Indian Ocean Pacific Ocean Southern Ocean Each one of these regions is different from the others in some specific ways. Atlantic Ocean The Atlantic Ocean is a relatively narrow body of water that snakes between nearly parallel continental masses covering about 21% of the Earth's total surface area. This ocean body contains most of our planet's shallow seas, but it has relatively few islands. Some of the shallow seas found in the Atlantic Ocean include the Caribbean, Mediterranean, Baltic, Black, North, Baltic, and the Gulf of Mexico. The average depth of the Atlantic Ocean (including its adjacent seas) is about 3300 meters (10,800 feet). The deepest point, 8605 meters (28,232 feet), occurs in the Puerto Rico Trench. The Mid-Atlantic Ridge, running roughly down the center of this ocean region, separates the Atlantic Ocean into two large basins. Many streams empty their fresh water discharge into the Atlantic Ocean. In fact, the Atlantic Ocean receives more freshwater from terrestrial runoff than any other ocean region. This ocean region also drains some of the Earth's largest rivers including the Amazon, Mississippi, St. Lawrence, and Congo. The surface area of the Atlantic Ocean is about 1.6 times greater than the terrestrial area providing runoff. Arctic Ocean The Arctic Ocean is the smallest of the world's five ocean regions, covering about 3% of the Earth's total surface area. Most of this nearly landlocked ocean region is located north of the Arctic Circle. The Arctic Ocean is connected to the Atlantic Ocean by the Greenland Sea, and the Pacific Ocean via the Bering Strait. The Arctic Ocean is also the shallowest ocean region with an average depth of 1050 meters (3450 feet). The center of the Arctic Ocean is covered by a drifting persistent icepack that has an average thickness of about 3 meters (10 feet). During the winter months, this sea ice covers much of the Arctic Ocean surface. Higher temperatures in the summer months cause the icepack to seasonally shrink in extent by about 50%.

3 Indian Ocean The Indian Ocean covers about 14% of the Earth's surface area. This ocean region is enclosed on three sides by the landmasses of Africa, Asia, and Australia. The Indian Ocean's southern border is open to water exchange with the much colder Southern Ocean. Average depth of the Indian Ocean is 3900 meters (12,800 feet). The deepest point in this ocean region occurs in the Java Trench with a depth of 7258 meters (23,812 feet) below sea level. The Indian Ocean region has relatively few islands. Continental shelf areas tend to be quite narrow and not many shallow seas exist. Relative to the Atlantic Ocean, only a small number of streams drain into the Indian Ocean. Consequently, the surface area of the Indian Ocean is approximately 400% larger than the land area supply runoff into it. Some of the major rivers flowing into the Indian Ocean include the Zambezi, Arvandrud/Shatt-al-Arab, Indus, Ganges, Brahmaputra, and the Irrawaddy. Because much of the Indian Ocean lies within the tropics, this basin has the warmest surface ocean temperatures. Pacific Ocean The Pacific Ocean is the largest ocean region covering about 30% of the Earth's surface area (about 15 times the size of the United States). The ocean floor of the Pacific is quite uniform in depth having an average elevation of 4300 meters (14,100 feet) below sea level. This fact makes it the deepest ocean region on average. The Pacific Ocean is also home to the lowest elevation on our planet. The deepest point in the Mariana Trench lies some 10,911 meters (35,840 feet) below sea level. About 25,000 islands can be found in the Pacific Ocean region. This is more than the number for the other four ocean regions combined. Many of these islands are actually the tops of volcanic mountains created by the release of molten rock from beneath the ocean floor. Relative to the Atlantic Ocean, only a small number of rivers add terrestrial freshwater runoff to the Pacific Ocean. In fact, the surface area of the Pacific is about 1000% greater than the land area that drains into it. Some of the major rivers flowing into this ocean region include the Colorado, Columbia, Fraser, Mekong, Río Grande de Santiago, San Joaquin, Shinano, Skeena, Stikine, Xi Jiang, and Yukon. Some of larger adjacent seas connected to the Pacific are Celebes, Tasman, Coral, East China, Sulu, South China, Yellow, and the Sea of Japan. Southern Ocean The Southern Ocean surrounds Antarctica and occupies about 4% of the Earth's surface or about 20,327,000 square kilometers (7,846,000 square miles). Relative to the other ocean regions, the floor of the Southern Ocean is quite deep ranging from 4000 to 5000 meters (13,100 to 16,400 feet) below sea level over most of the area it occupies.

4 Continental shelf areas are very limited and are mainly found around Antarctica. But even these areas are quite deep with an elevation between 400 to 800 meters (1300 to 2600 feet) below sea level. For comparison, the average depth of the continental shelf for the entire planet is about 130 meters (425 feet). The Southern Ocean's deepest point is in the South Sandwich Trench at 7235 meters (23,3737 feet) sea level. Seas adjacent to this ocean region include the Amundsen Sea, Bellingshausen Sea, Ross Sea, Scotia Sea, and the Weddell Sea. By about September of each year, a mobile icepack situated around Antarctic reaches its greatest seasonal extent covering about 19 million square kilometers (7 million square miles). This icepack shrinks by around 85% six months later in March. How Geography Influences Cruise Destinations When planning which ports of call a cruise ship should visit, climate is perhaps one of the most important considerations that a cruise line has to make to ensure the safety and comfort of the passengers. If a cruise ship sailed to a particular part of an ocean at a particular time of the year, then the safety and comfort of the passengers could be directly affected. The same holds true for the shore excursions that may be offered in port. To avoid potential passenger discomfort, cruise ships tend to avoid ports of call in parts of the world where geography, seasonal variations and climate often result in difficult sea conditions. The North Atlantic, for example, is renowned by seafarers for extreme weather. However, with records of tidal variations, knowledge of weather patterns and the technology available today, cruise companies can predict where and when their ships can travel to safely, which means that practically all of the world's oceans, seas and ports can be visited at one time or another. Weather Cycles Weather patterns are complex and are influenced by many factors, including the sun's rays, the world's rotational axis (which creates seasonal variations), the land masses and oceans, currents and the moon's gravitational pull (which creates tidal variations). Northern and Southern hemispheres experience seasons at opposite times of the year, reflecting the position of the world as it orbits the sun. Tropical Zones The point where the Earth is closest to the Sun is known as the equator. The Tropics of Cancer and Capricorn are lines of latitude that run parallel to the equator. These two boundaries define the region that is known as the "tropics". Points above and below the equator can be affected by bad weather and storms, although the equator can be calm. The weather effect when the wind and sea are calm is known as the doldrums. Tropical cyclones can create winds in excess of 120 km per hour. They are triggered by suppressed heat, water condensation and cloud formations. Through careful monitoring these patterns can be predicted and cruise ships can be pre-warned and take the necessary measures. Most modern cruise ships are designed for cruising in moderate conditions, so itineraries are partly influenced by weather patterns.

5 Nautical Times and Time Zones Cruising has indeed made the world a smaller place. As the cruise industry has developed, cruise line companies have expanded their itineraries to cover hundreds of worldwide destinations. Most cruise lines will carry crewmembers and passengers through numerous time zones on a single cruise and as crew professionals you need to learn about time changes and the world time zones. Time Changes Throughout the world the pattern of day and night varies because of the natural rotation of the earth. As a result of this the earth's surface is divided into 24 time zones. Due to the fact that cruise ships can carry crewmembers and passengers through numerous time zones on a single cruise, the cruise industry typically uses a single worldwide standard time. This time is referred to as Greenwich Mean Time (GMT) or "Zulu Time". As a crewmember it is important to understand this. Why GMT? The world's surface is divided into horizontal and vertical degree lines. These are referred to as lines of longitude for the vertical lines and lines of latitude for the horizontal line. The time differences are measured East or West of the 0 degree line of longitude, which passes through Greenwich in England. This is referred to as Greenwich Mean Time (GMT) which is the internationally agreed standard time. West of Greenwich is time minus (-) GMT East of Greenwich is time plus (+) GMT Standard Time Zones of the world The map below shows the world time zones measured in minus and plus hours either east or west of Greenwich Mean Time. It is important to note that in the cruise line world Greenwich Mean Time is also referred to as ZULU time. In the past, time on a ship's clocks and in a ship's log had to be stated along with a "zone description" and a letter suffix was added to each zone description which were vocalized using the phonetic alphabet. The letter Z for Zulu was assigned to the Zero Zone (GMT), leading to the use of the term "Zulu Time".

6 Being able to calculate and convert the local times from one city to another is important for all crewmembers. Embarkation means to go aboard a cruise ship at the start of its journey. Debarkation means to leave or sign-off a cruise ship at the end of its journey. The embarkation and debarkation times you will see printed in itinerary timetables are always the local times. In addition times for crew signing off duty at the end of a contract may also be stated in both local and GMT times. There are two simple steps to follow if you want to convert the time in one country or city to the time in another. Convert the time in one city to GMT. Convert GMT to the time in the other city. See the two steps below: Step #1 Step #2 Find the number of longitude lines between you and the Prime Meridian in Greenwich, England. Remember when you were in school learning geography, and looking at the maps with those lines running north and south, from pole to pole? Those are longitude lines and they are used in calculating coordinates for travel and also for calculating time, relative to the Prime Meridian. Count the number of north/south longitude lines between you and the Prime Meridian. Between the Prime Meridian in England, and Chicago, Illinois, there are six longitude, or meridian lines. Determine if you're east or west of the Prime Meridian. Look at the world map again. If you're west of the Prime Meridian, your GMT will be ahead of, or minus, the time at the Prime Meridian. If you are east, your time will be after, or plus, GMT. Put the minus or plus sign in front of the number you found from the previous step and that's your GMT. Chicago is west of the Prime Meridian, so Chicago will be - 6 GMT, or six hours less than the time at the Prime Meridian. Close out this article and head back to ship as we prepare for destination #4