Australia Dive Master Rescue

Cairns is one of the most popular places in the world where people learn to dive during their holiday. Dive schools in Cairns usually have regular open water classes with many students.

For those who want to become dive professionals, it is the ideal place to learn how to teach diving as there are so many students learning each day. Safety comes first. But also quality and efficiency are to be learned here. To assist an instructor in a large open water class prepares you well for "the real life" out there.

Taking a divemaster course in Cairns is a great way to gain experience. Also, it is a good base if you wish to continue to an instructor course. Most courses offered in Cairns are PADI courses. The course is at least 18 days long, but plan for 21 days, to be on the safe side. Part of the course is to assist an instructor in teaching 2 Open Water courses. When available you may also assist in Advanced and Rescue courses.

You get 2 live aboard dive trips (each 3 days/2 nights long) to the Great Barrier Reef. During these trips you will get up to 20 dives. Some are training dives and some just recreational dives.

During the course you get familiar with the diver training process and you will gain an awareness of typical student problems. Also you will learn how to supervise and control divers in general. You will learn to perform diving skills to demonstration level and, of course, you learn a lot of theory and take written exams. You need to be pretty fit too, as there are a few swimming tests.

Minimum requirements are:

• You should be at least 18 years old
• Have a PADI Rescue Diver certification
• A valid diving medical to Australian standard
  more details on dive medicals
• No less than 20 logged Scuba Dives when starting the Divemaster course, but to complete the PADI Divemaster certification you will need to have completed 60 logged Scuba Dives.
• Price for the 18-day Divemaster Course costs up to AU$ 1995 (until 31 March 2009). Please e-mail us if you are interested in this course.

THE OCEAN FLOOR

The ocean floor is home to many unique communities of plants and animals. Most of these marine ecosystems are near the water surface, such as the Great Barrier Reef, a 2,000-km-long coral formation off the northeastern coast of Australia. Coral reefs, like nearly all complex living communities, depend on solar energy for growth (photosynthesis). The sun's energy, however, penetrates at most only about 300 m below the surface of the water. The relatively shallow penetration of solar energy and the sinking of cold, subpolar water combine to make most of the deep ocean floor a frigid environment with few life forms.In 1977, scientists discovered hot springs at a depth of 2.5 km, on the Galapagos Rift (spreading ridge) off the coast of Ecuador. This exciting discovery was not really a surprise. Since the early 1970s, scientists had predicted that hot springs (geothermal vents) should be found at the active spreading centers along the mid-oceanic ridges, where magma, at temperatures over 1,000 °C, presumably was being erupted to form new oceanic crust. More exciting, because it was totally unexpected, was the discovery of abundant and unusual sea life -- giant tube worms, huge clams, and mussels -- that thrived around the hot springs.

tube

Temperature, Heat Capacity and Heat Conductivity

Temperature, Heat Capacity and Heat Conductivity The heat capacity of seawater is 3134 times greater than that of air. Water has insignificant heat conductivity. That is why distribution of heat to greater depths is very slow and is mainly achieved through convection.
The highest temperature of water is registered to occur between 3 and 4 p.m., and the lowest – a couple of hours after sunrise. There are three temperature layers of seawater: surface layer (epilymnion), intermediate layer (metalymnion), and deepest layer (hypolymnion). The thickness of the former two layers varies with the weather, season, and currents. The temperature of the surface layer is almost constant, being between 19 and 25ºC in the summer. As the deepest layer begins, temperature drops by a few more degrees and it remains constant thereafter (7–9ºC). That is the temperature of sea depths and it does not depend on the season.
Water Motion Water motion constitutes sea currents and waves. The reason for the formation of currents might be the different density of water, constant winds, etc. Ocean currents are usually caused by constant winds, whereas local ones are mainly due to the character of coastlines. According to he direction of their flow, currents can be classified as vertical or horizontal. There are three main types of waves: wind waves, standing waves, and seismic waves.
Wind is the main reason for the formation of waves. The process of wave formation can be divide into different stages. When the speed of wind is less than 1m/s, air motion does not affect the surface of the water. If wind intensifies, these rows of waves become irregular and peaks appear, which are due to the different pressure at the front and at the back of the wave. At a greater speed of wind large waves are formed, running in parallel rows. Th largest waves reaching hundreds of meters continue even when the wind has ceased. They create the so-called dead drift.
Standing waves are formed when the level of the water rises at one coast and in the same time drops at the other. A sudden decrease of atmospheric pressure at one of the coasts, appearance of strong wind or heavy rain can all be the causes for standing waves. The fluctuation of the sea level may reach 80cm, which is dangerous for vessels at the harbors.
Seismic waves are formed because of underwater earthquakes. A vessel that is nest the site of the earthquake experiences a hydraulic blow which is why old maps frequently contain non-existent reefs. Seismic waves are often present in the Hawaii region where they have the special name zunami. Such waves are formed in the Pacific Ocean, the Mediterranean, the Caribbean Sea, and the Malaya Archipelago as well. Sometimes, these waves reach the height of 35m and are dangerous not only for the ships but also for the native population because of their destructive power.Waves change their form when they reach shallow regions. When the depth becomes equal to the height of the wave, the water particles no longer move in a circle: their orbit becomes elliptical. The length of the waves decreases and the height increases. The front slope of the wave becomes vertical, the top is inclined forward, then it falls and eventually destroys the wave. This phenomenon is called a surf. Its force may reach up to 38 tonnes/m2.