Wednesday, May 27, 2009

mengenali kayak...

A kayak is a small human-powered boat. It typically has a covered deck, and a cockpit covered by a spraydeck. The kayak was used by the native Ainu, Aleut and Eskimo hunters in sub-Arctic regions of northeastern Asia, North America and Greenland. It historically was, and often still is, or can be, propelled by a double-bladed paddle in the hands of a sitting paddler. Modern kayaks come in a wide variety of designs and materials for specialized purposes. Kayaks are in some parts of the world referred to as canoes.


Kayaks are often used to get closer to marine animals, for example sea otters
Traditional kayaks typically accommodate one, two or occasionally three paddlers who sit facing forward in one or more cockpits below the deck of the boat. If used, the spraydeckor similar waterproof garment attaches securely to the edges of the cockpit, preventing the entry of water from waves or spray, and making it possible, in some styles of boat, to rollthe kayak upright again without it filling with water or ejecting the paddler.
Inuit/ Eskimo Kayaks are a type of a generic class of boat of Canoe Shape. European Canoeing clubs and associations of the 19th Century used similar craft to what are now called Kayaks, but referred to these as types of Canoe. This explains the naming of the International and National Governing bodies of the sport of Canoeing. John MacGregor (sportsman)

Sea kayaks

Kayaking in a double on Lake Union in Seattle, Washington, United States
The sea kayak, though descended directly from traditional designs and types, is implemented in a wide variety of materials, and with many distinct design choices. Sea kayaks as a class are distinct from whitewater kayaks and other boats by typically having a longer waterline (emphasizing straight travel through the water over extreme maneuverability), and provisions for below-deck storage of cargo. Sea kayaks may also have rudders or skegs (also for enhanced straight-line tracking), and such features as upturned bow or stern profiles for wave shedding. Modern sea kayaks often have two or more internal bulkheads to provide watertight internal sections for flotation and waterproof storage. Sea kayaks, unlike most whitewater kayaks, may be built to accommodate two or sometimes three paddlers. Certain sea kayaks can even be used for surfing.


A paddler in a sit on top kayak explores Kealakekua Bay in Hawaii.
Sealed-hull (unsinkable) craft were developed in the past for leisure use, as derivatives from surfboards (e.g. paddle or wave skis), or for surf conditions. Variants include planing surf craft, touring kayaks, and sea marathon kayaks. Increasingly, manufacturers are building leisure 'sit-on-top' variants of extreme sports craft these are normally built using polyethylene to ensure strength and keep the price down[5] , often with a skeg (fixed rudder) for directional stability. Water that enters the cockpit drains out through scupper holes - tubes that run from the cockpit to the bottom of the hull. Sit-on-top kayaks usually come in single and double (two paddler) designs, although a few models accommodate three or four paddlers. Sit-on-top kayaks are particularly popular for fishing and SCUBA diving, since participants need to easily enter and exit the water, change seating positions, and access hatches and storage wells. Ordinarily the seat of a sit-on-top is slightly above water level, so the center of gravity for the paddler is higher than in a traditional kayak. To compensate for the center of gravity, a sit-on-top is often wider than a traditional kayak of the same length, and is considered slower as a result.

Whitewater kayaks

Whitewater kayak
Plastic whitewater kayaks are rotomoulded in a semi-rigid, high impact plastic, which is usuallypolyethylene. Careful construction is needed to ensure that the completed boat will remain structurally sound when subjected to the incredible forces of fast-moving water. A plastic hull allows these kayaks to bounce off rocks without suffering leaks, although they can be scratched and eventually worn through with enough use. Standard whitewater boats are shorter than other types of kayaks, ranging from 4 to 10 feet (1.25 to 3 metres) long. There are two main types of whitewater kayak, and most experienced paddlers own one of each.
One type, known as the playboat, is short, with a scooped bow and blunt stern. These are slow and not extremely stable, but they are incredibly maneuverable. Their primary use is performing tricks in single water features or short stretches of river. In playboating or "freestyle" competition (also known in some parts of the US as "rodeo" boating), kayakers exploit the complex currents of rapids to do a series of tricks, which are scored for skill and style.
The other primary type is the creekboat, which gets its name from its purpose: running narrow, low-volume waterways. Creekboats are longer and have far more volume than playboats, which makes them faster and higher-floating. They are also designed to be very stable. Many paddlers use creekboats in "short boat" downriver races, and they are often seen on large rivers where their extra stability and speed may be necessary to get through the rapids.
Between the creekboat and playboat extremes is a general category called "river running" kayaks. These medium-sized boats are designed for rivers of moderate to high volume, and some, known as "river running playboats", are capable of basic playboating moves. They are typically owned by paddlers who do not have enough involvement in whitewater to merit the purchase of multiple more specialized boats.

Most whitewater kayakers consider fiberglass boats old-fashioned, but there are some types of kayak that work much better if made from fiberglass. Squirt boats and racing kayaks are among them.
Squirt Boating involves paddling both on the surface of the river and underwater. Squirt boats must be custom-fitted to the paddler in order to ensure comfort while maintaining the low interior volume necessary to allow the paddler to submerge him- or herself completely in the river.
Racing whitewater kayaks, like all racing kayaks, are made to regulation lengths and are generally made out of fibre reinforced resin (fiberglass) for speed. This makes them stiffer, lighter, and less readily scratched than plastic hulls, though they are more prone to breakage from impact. Repairs are often necessary, especially if the paddler is inexperienced. Slalom kayaks are flat hulled, highly manoeuvrable, and stable but not very fast in a straight line; downriver white water racers have a combination hull with a fast but unstable lower section similar to a flat water racer's hull flaring out into a wider section higher up similar to a slalom hull to provide stability in big water.

Racing kayaks

[edit]Flatwater racing kayaks

A typical racing K2 design, at the Canadian Masters Championships, 2005. Note the extremely narrow beam.
The three types of flatwater racing kayaks (sometimes termed 'sprint boats') are K1 (single paddler), K2 (two paddlers) and K4 (four paddlers). These boats are raced at the Olympic level by men and women over courses of 200 m, 500m, and 1000m (women compete on 1000 m since 1997). World Championship events:
  • distances: 200 m, 500m, 1000 m
  • boat units: men and women K1, K2, K4; men canoe C1, C2, C4 All units compete on all distances.Each country can send one unit per event.
Olympic events:
  • distances: 500 m, 1000m
  • events: men K1-K2 500m, K1-K2-K4 1000m; women K1-K2-K4 500m, men canoe C1-C2 500m, C1-C2 1000m Each country can send one unit per event.
Flatwater racing kayaks are generally made out of extremely lightweight composites such as Kevlar,carbon fiber, or fiberglass. They are not intended for any condition other than flat water. They are narrow, extremely unstable, and expensive, with a competitive K1 or K2 running in the US$2000 - US$4000 range. They require a good level of expertise to paddle well, but are extremely fast in the hands of proficient users. The beam of a flatwater boat is typically barely wider than the hips of the person who paddles it, allowing for a very long and narrow shape to reduce drag.
Due to their length (a K1 is 5.2m (17 ft) long and a k2 is 6.2m (20 ft) long), sprint boats come equipped with a rudder to help with turning. The rudder is controlled by the feet of the paddler (the foremost paddler in multi-person designs). In spite of this, these boats have a fairly large turning radius.
Flatwater racing kayaks are closely related to flatwater racing canoes, with both styles of boat usually training at the same club or with the same team, although it is rare for paddlers to compete in both canoes and kayaks.

Pedal kayaks

A special type of kayak using pedals allows the kayaker to propel the vessel with a propeller or underwater "flippers" attached to pedals in the cockpit, rather than with a paddle. This allows the kayaker to keep his or her hands free for steering the rudder, fishing and other activities.

Canoe/Kayak paddles

[edit]Materials and designs

Paddles commonly used in canoes consist of a wooden, fiberglass carbon fiber or metal rod (the shaft) with a handle on one end and a rigid sheet (the blade) on the other end. Paddles for use in kayaks are longer, with a blade on each end; they are handled from the middle of the shaft.

A kayak paddle. The colors are used for signal purposes by guides. (a) top view, (b) axial view
Kayak paddles having blades in the same plane (when viewed down the shaft) are called "un-feathered." Paddles with blades in different planes (such as in the image) are called "feathered". Feathered paddles are measured by the degree of feather, such as 30, 45, or even 90 degrees. The paddle in the image to the right is feathered around 15 degrees. Many modern paddles can be adjusted by the user for feathered or unfeathered settings. The shaft is normally straight but in some cases a 'crank' is added with the aim of making the paddle more comfortable and reducing the strain on the wrist. Because the kayak paddle is not supported by the boat, paddles made of lighter materials are desired, it is not uncommon for a kayak paddle to be two pounds (32 ounces) or less in weight.


A Rapa Nuirapa, a ceremonial dance paddle.
The paddle is held with two hands, some distance apart from each other. For normal use, it is drawn through the water from front (bow) to back (stern) to drive the boat forwards. The two blades of a kayak paddle are dipped alternately on either side of the kayak. A paddle is distinguished from an oar in that the paddle is held in the user's hands and completely supported by the paddler, whereas an oar is primarily supported by the boat.

[edit]Other types

On mechanical paddle steamers, the motorized paddling is not done with a mass of paddles or oars but by rotating one or a few paddle wheels (rather the inverse of a water mill)
Racing paddles also have special designs. They are generally less flat and are curved to catch more water which will enable racing paddlers to maximize the efficiency of their stroke.
Paddle shifters are special kinds of paddles since it is used in cars equipped with a semi-automatic transmission. They are operated back and forth.

Tips Pelajar Cemerlang...

Mulakan dari awal
Pelajar yang cemerlang membuat persediaan awal apabila akan menghadapi peperiksaan tidak kira sama ada ujian bulanan, peperiksaan penggal atau peperiksaan yang sebenarnya. Persediaan awal akan membezakan pelajar yang berjaya dengan yang gagal. Persediaan awal ini termasuklah mengadakan ulangkaji, berbincang dengan rakan-rakan, meminta nasihat guru, meneliti buku-buku model jawapan dan sebagainya lagi.
Jangan jadi 'bidan terjun' ke dewan peperiksaan.

Sentiasa bersedia
Pelajar yang cemerlang sentiasa bersiap sedia untuk menghadapi sebarang bentuk ujian atau peperiksaan yang bakal diadakan oleh pihak sekolah (ujian bulanan, peperiksaan penggal) atau oleh pihak kementerian (peperiksaan yang sebenarnya). Pelajar yang berjaya ialah pelajar yang sanggup dan mampu menghadapi peperiksaan bila-bila masa sahaja. Bersediakah anda andainya peperiksaan diadakan esok? Pelajar cemerlang akan berkata 'Ya!' Kalau anda peminat 'The Rock' anda akan berkata 'Just bring it on..!'

Dapatkan bantuan guru
Pelajar yang cemerlang mendapatkan bantuan guru atau kawan-kawan sekelas yang lain apabila gagal mengikuti kelas di atas sebab-sebab tertentu. Misalnya apabila pelajar sakit dan tidak dapat hadir ke kelas, pelajar perlulah mendapatkan bantuan kawan-kawan untuk mendapatkan nota-nota pelajaran, atau mendapatkan penerangan guru bagi pelajaran yang telah tertinggal itu.
Hormati guru
Pelajar yang cemerlang sentiasa menghormati guru sama ada semasa guru sedang mengajar di dalam kelas atau sewaktu berada di luar kelas. Guru adalah sumber ilmu. Oleh itu sentiasalah menghormati guru yang memberikan kita ilmu.

Tubuhkan kumpulan studi
Pelajar yang cemerlang mengadakan kumpulan perbincangan (study group) bersama rakan-rakan yang mempunyai visi dan agenda yang sama iaitu kejayaan dalam peperiksaan. Tapi jangan tubuhkan kumpulan studi yang akhirnya menjadi kumpulan bersembang! Carilah rakan-rakan yang ragin dan gigih. Tinggalkan rakan-rakan yang hanya suka temberang.

Sediakan jadual waktu
Pelajar yang cemerlang menyediakan jadual waktu untuk merancang pembelajaran pelajar di luar sekolah. Minta nasihat guru atau abang-abang yang berpengalaman untuk mendapatkan corak jadual yang sesuai dan efektif.
Jadual ini mestilah dipatuhi.

Makanan seimbang
Pelajar yang cemerlang menjaga dan mengawal pemakanan dengan memakan makanan yang seimbang. Ini akan menjamin kesihatan badan yang baik dan otak yang dapat berfikir dengan lebih lancar. Pilih jenis makanan yang sesuai untuk minda dan kesihatan tubuh badan.

Pelajar yang cemerlang menjaga sembahyangnya. Bagi pelajar Islam, tunaikan sembahyang lima waktu seperti mana yang telah disyariatkan oleh agama. Bagi pelajar bukan Islam yang lain, lakukan amalan ibadat agama masing-masing.


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