Rotomolding A fabrication technique used to make kayaks and decked canoes (and a variety of other useful, hollow objects). A multi-part mold is rotated while plastic material injected into the hollow cavity of the mold sets. The mold is then opened and the boat hull is removed, cleaned and finished.
Royalex A laminate made of at least five layers of plastic used primarily for open canoe hulls. (Often incorrectly referred to as ABS.) An inner core of ABS foam is sandwiched between two or more layers of solid ABS sheeting and coated with outside layers of vinyl. It is very rugged and very heavy. Lighter weight versions are available that sacrifice some durability. The outer vinyl layer makes the hull slide well over rocks, but it is not very abrasion resistant, and a little of the surface peels of each time it glides over a rock. Also, fastening outfitting to the slippery hull is tricky.
Slalom Racing Racers, using high performance canoes and kayaks, race one-at-a-time down a fixed course marked by hanging poles that form gates. They are timed. Usually they get two runs, the best time counting. Paddlers must pass through some gates going up current, others going down current. Hitting the poles or missing the gates entirely results in time penalties.
Sluice Water going through a very narrow passage between two rocks at high speed. To be avoided, unless you know your boat will fit and you are sure you want what's at the bottom.
Spray Skirt or Spray Deck A garment worn snugly around the waist of the paddler that seals to the cockpit rim of a decked boat, typically with an elastic cord. The spray skirt is usually made of fabric-coated neoprene or rubberized cloth. It keeps water from entering the boat, even when the paddler is leaned over or upside down.
Standing Wave When faster water meets slower water, it causes a wave to build up. They're fun to run, and generally benign, but can swamp open canoes and flip any boat if shaped right and big enough.
Strainer The deadliest trap on the river! When water pours through the branches of a fallen tree, or through a pile of rocks or ice, it produces a strainer. When you drain a pot of spaghetti into a strainer, the water goes through and the spaghetti is trapped. Now imagine that you are the pasta and that the pot of water never runs out. That's what happens if you, with or without your boat, get into a strainer. Even with a gentle current, strainers are bad. They can pin you below the surface of the water and you can't get out.
....If possible, take a swift water safety course and practice dealing with strainers. If you realize you can't avoid a strainer, climb on to it, climb over it! If you are swimming in the water, and about to wash into a strainer, swim headfirst as aggressively as possible toward it and climb onto, up and over it. Move as if your life depends on it. It does!
Surf 1) Surfing the standing waves in a river is much like surfing the moving waves in an ocean. Surfing is done by getting onto the upstream face of a wave. There, gravity tries to pull the boat down the hill (upstream), while the friction of the flowing water tries to move it down river, which is back up the hill. The boat balances and stays more or less in on spot on the wave. By means of various leans and paddle strokes, the paddler can move the boat on the wave, often swapping ends or spinning it. Side surfing is done with the boat sideways to the current, sitting in or above a hydraulic. The paddler can spin the boat and do a variety of other tricks.
2) Canoes and kayaks can surf moving waves on the ocean just like a surfboard. In fact, most surf very well. However, in moderate to big surf, this can be dangerous. When you wipe out, you will be in waves with a water-filled boat that may weigh several hundred to several thousand pounds. Decked boaters may find that their best roll won't work in two feet of foam; and you can be slammed into the beach several times before you can wet exit. Wear a helmet and good luck, this is a tough sport! If you are trying to land a boat in surf, stay behind the crest of a wave and run it up on the beach as quickly as possible.
Thwart A structural member that runs across the width of an open canoe, usually of wood or aluminum tubing. A paddling thwart is a type of seat. It usually consists a piece of wood tilted forward so the kneeling paddler can rest his butt on it. Once popular because of their light weight, paddling thwarts are seldom used and definitely not recommended for safety reasons. If the boat were to pin and collapse, the paddler's legs could be trapped under the thwart.
Tidewater Water influenced by the tides. It includes the ocean, bays and the lower parts of rivers. Wind and waves are two dominant forces the paddler has to deal with tidewater, as are tidal currents, river currents and ocean currents.
Touring Generally, paddling on flatwater, mild whitewater or easy broadwater, done as a day trip or a series of day trips. It often includes camping trips of a few days. See Tripping.
Tripping Extended travel by canoe or kayak over any type or on a wide range of water types, usually as part of a group. Generally, this means carrying camping gear and provisions for extended travel. Often done in remote areas.
Tumblehome See Hull Design.