Key terms and concepts in raftingWater obstacles
Interesting for all kinds of rafting obstacles occur on rivers and artificial water bodies in case of appropriate riverbed inclination (not less than 3m abatement of water level). The obstacles may be formed due to accumulation of stones and broken pieces of rocks in the riverbed, stream heterogeneous, river twisting and all the mentioned combined. The difficulty of obstacles rises according to their sizes, stream speed and weather conditions. The most typical water obstacles are falls, rollers, barrels, shivers. Concentrating in a particular river section, they form falls. Owing to these obstacles, rafting is related to extreme sport.
The obstacles complexity can be estimated with the help of different scales of complexity categories. In the most popular two, international and home, the obstacles are divided into six categories, from the easiest – the first – to the most difficult and dangerous – the sixth. The international scale classifies technical difficulties of separate river sections or obstacles, while the home one, besides all mentioned, takes into consideration trip autonomy and the length of the rout in whole. Riverbed inclination and water rate, obstacle’s elements concentration, its length, possibility or impossibility to get round the main rapids elements on calm water, as well as the way it can endanger sportsman’s life – all these are taken into consideration when estimating a water obstacle. Sometimes obstacle’s level of complexity is estimated separately for different types of sport ship.
Falls (overfalls, waterfalls) are formed by water stream, which flows down from one stone, an accumulation of stones or a cascade in the riverbed. High steep (more than 45º) falls, which are of the same height as the vessel’s length, are difficult to go through. Despite the beauty and greatness, the waterfalls are both most difficult and dangerous, when a mass of water sharply falls from the considerable height (sometimes more than tens metres). Almost always falls combine with other obstacles – rollers and barrels. The rapids are just the reason of overkill and rafting needs additional skills on such routs.
Rollers (standing waves), immovable relatively to the banks, are formed when water runs on sloping falls, usually in the shape of a track with a few rollers. Heavy rollers with a foamy peak can reach the height of three and more metres in fast water flow; they are very dangerous and difficult to go through.
Barrels (foamy pits) are formed in places where water falls from steep falls, a section with foamy water and strong vertical circulations appears with it, and it brings counter flow on the barrel surface. When going through such section, the raft, kayak or canoe dives into the foamy pit, the counter flow slows the craft down as the water falling from up above can throw it over. Catamaran is difficult to throw over because water flows between the balloons and does not flood the cockpit.
Rapids are a combination of obstacles (rollers, barrels, above-water rocks and reefs) which forms up a river section of the heightened complexity. When a few rapids combine one after another, they are called cascades. Their most dangerous and difficult variety is the canyon cascades, where the water flow is limited by steep cliffs, creating numerous specific obstacles of the heightened complexity, thus creating difficulties with providing proper life security during rafting.
Today, sport rafting is possible on the rivers with water flow from five cubic metres per hour and riverbed slope up to 100m/km. Waterfalls up to 30m high, rollers and barrels of the same geometrical sizes that do not exceed the vessel length twice are considered suitable for rafting.
Swift course – the river section where water flows fast without any obstacles.
Rotator – an exercise to train spiral rising, the idea of this exercise is to be used on one side to have a rotation effect in the water. Spiral/ spirally – the way to put the vessel in standing position after it turns over with the help of a long arc stroke under the water.
Herma – a leakproof bag.
Hydra – a wetsuit.
Hortex– an air-permeable waterproof fabrics.
Hreblo – ukr. slang, meaning oar.
Two, three etc. – the level of river or rapids complexity. The first is the easiest; the sixth is the most difficult.
Deck – upper fixed part of a kayak, which is above water.
Arc stroke – a stroke to form an arc. As a rule is used to turn the vessel sharply.
Graft – a person, who stands by on the bank with a safety rope.
Biting – a phenomenon, when water head pressures the upper side of the vessel and it can cause overturn.
Hook – a kind of a stroke, which allows stabilizing the vessel when the current changes rapidly.
Canoe – a vessel with a cockpit, equipped with a device, which allows sitting with knees bended, it is set in motion with a one-blade oar.
Cat/catamaran – a sailing vessel for rafting with twin hulls held parallel by a rigid framework.
Catheter – a long slender flexible tube for blowing up vests, balloons and other rafting equipment.
Kayak – a small light canoe-like boat, which is set in motion with a two-blade oar.
Keelson – a longitudinal beam fastened to the keel of a vessel for strength and stiffness.
Cockpit – an enclosed or recessed area of the boat with a rafter.
Pit – a few barrels that make semicircle in a way that makes water fall from the pit’s wall.
Crocodile – slang, a word to describe a water obstacle when water current turbulence inevitably pressurizes the boat’s upper side and creates an impression of “ingestion” of the boat.
Lagom – the position of the boat being with its one side to the water flow.
Neoprene – a synthetic rubber obtained by the polymerization of chloroprene. It is resistant to water and is used in waterproof products, such as diving suits. When it gets wet, it heats the water at the expense of the body temperature, which allows staying in icy water up to 15-20min.
Support – an oar movement, meant to help avoid a turnover.
Eye – an upper annular part of cockpit through which rafter gets into the raft or catamaran.
Stretch – a river or lake section without any current or a very slow one.
Toadstool – a water obstacle created by a strong undercurrent, which gushes up, creating a mushroom-like protuberance.
Rowing-ups – a homemade construction on rafts used for propping up an oar.
Hold-down – rapids place where the main canal is pressed to one of the banks. Usually hold-downs occur at the bend of the river with a strong current.
Draw-up – an oar side movement, performed to draw up water to the boat. An in-front rafter uses it for a rapid turn.
Channel – a narrow channel of the river, which links two lakes.
Cannon – a seat for an oarsman on catamaran in a shape of tripod, it can also be pneumatic.
Raft – a widely spread buoyant platform of logs, planks, etc., used as a vessel or moored platform for rafting down the difficult rivers, used doth commercially and sports.
Rafting – an extreme kind of sport, going down the rough (white) water. Sometimes rafting means any water activity when rafts are used, e.g. raft fishing.
Rafter – anyone, whose bottom touched the raft board just once, holding an oar and rowing (even chaotically) down the white water.
Lever – the way to put the vessel in standing position after it turns round with the help of an arc stroke, which is directed athwart to the hull in vertical plane.
Candle – when a vessel is in vertical position in water.
Fall – a water obstacle with gently sloping water flow.
Saving rope/car rot/grenade – a rope with a cork-float and carbine on its end that is used for standing by while going down the rapids.
Waist – catamaran carcass.
Stringer – a canoe part, which is parallel to keelson.
Bench – a rapids part where rapid water altitude drop is absent.
Back water – slowing down by fixing the oars in water.
Traverse – going against the current.
Seal /Cliff start – to jump into the water being on board from any prominence.
Catching – rapids place, where the flow runs against the main current or is absent. They usually are behind the stone ridges, on the inner sides of bends, behind big stones without water etc.
Stretcher – a fixed board across a boat on which an oarsman braces his feet.
Washboards – a vertical plank-like shield fastened to the gunwales of a boat to prevent water from splashing over the side.
Apron – a canoe upper covering, which prevents from water to get inside.
Moor – to fasten or be fastened securely in one place.
Shivers/rolls – small rapids with no category, which has many prominent stones thus, making it difficult to go through.
Skin/galosh – waterproof canoe covering.
Rib – a part of canoe which is perpendicularly fixed to the keelson and supports all stringers.
Rod – a place of an oar where blades fix.
Skirt – a waterproof part of the boat (raft, canoe, kayak) one part of which is fixed by a hoop to on apron and the other covers the oarsman’s body to protect him/her from water.
Tongue – the main direction of the current.