Like canoes, kayaks come in a variety of shapes and sizes depending on the intended use. While canoes are paddled with a single blade paddle, kayaks are usually paddled with a double bladed paddle. You always sit in a kayak but you usually kneel in a canoe. Kayaks usually have a deck while canoes do not. The hole in the deck where you sit is called the cockpit.
All these rules have exceptions, including the names of the boats. In Europe, kayaks are called canoes and canoes are called Canadian canoes. There are decked canoes, that look like kayaks, except you kneel in them. Marathon canoes have seats. Some kayaks have no decks (they are called sit-on-tops).
Kayaks are classified according to their use and the number of paddlers they are made for. The touring boats are longer. White water boats are shorter with more rocker. The shortest white water boats are the "steep creek" boats and the "play boats." The longest touring boats are the sea kayaks for multiple paddlers and the sprint racing kayaks. The sea kayaks can come with rudders or skegs to help them track better. The white water play boats are very tubby to help them surf waves better. Speaking of surfing, there is even a special type of kayak intended for surfing ocean waves.
If a kayak is made for one person, it is called a K-1. A two person kayak is a K-2. For races, the sex of the paddler is included. K1-W is women's single kayak. Just for the record, that decked canoe I mentioned earlier is called a C-1 and an open, two person canoe is called OC-2. If that canoe is paddled by a man and a woman it is called OC2-M -- open canoe, mixed.
Most kayaks are made from synthetic materials. The most common are
fiberglass, kevlar and polyethelyene. All synthetic boats, both canoes
and kayaks, need some kind of floatation or they will sink if they
fill with water during a capsize. Some kayaks, most usually sea
kayaks, have air chambers separated from the cockpit by bulkheads.
These air chambers are often accessable through water tight hatches
and can be used for gear storage. Whitewater boats usually have foam
bulkheads to reinforce the boats. This foam has enough floatation to
keep the boat barely afloat. To be safe, more floatation is needed.
That floatation is provided by air bags or "float" bags.
These are usually vinyl or coated nylon and they are inflated with a
tube containing a valve.
(To be continued...)