If you think kayaking can be done on only calm water of lake or river, then it is not likely that kayaking can be done on any water surface. Whitewater kayaking is more popular than ocean kayaking; ocean kayaking is also admired by many people. Ocean kayaking is great alternative for surfing.
Normally kayaks are slender boats used for sailing on still lake waters. So to use such kayaks on ocean some modifications is required, they have to adopted to always changing ocean's unpredictable weather and huge brute strength of ocean. Considering this many changes are done normal rigid kayak to transform it into ocean kayak. So it is well said about ocean kayak that "Ocean kayaks are bit different and difference make them better".
Most significant adaptation in ocean kayaks is that they are huge; means have longer length than normal kayaks. These ocean kayaks are about fifteen plus feet longer and about 26 inches wider. Cockpit of ocean kayaks can be built as per your specification if you want it large choose larger, if you want it small, choose smaller.
Modern ocean kayaks can be made up of many different types of materials, sizes and in many different designs. Two main types in ocean kayaks are rigid kayaks and folding kayaks. There many different innovations are done with traditional craft and modern technology. Some new designs are recreational kayaks and sit on top kayaks, inflatable kayaks, surf kayaks or surf skies.
The most common size of an ocean kayaks is in between 12 to 15 feet and usually kayaks long lengths are built for two paddlers. Ocean kayaks usually 18" to 28" wide but some special type of kayaks like surf skies, which is specially designed for wave surfing is very narrow. Longer length of ocean kayaks increases their ability to sailing in straight line. And wider space allows more storage area.
Ocean kayaks can be made using many different types of material like rotomolded polyethylene, carbon Kevlar or more often using fiberglass or even sometime local material like foam core or carbon fibers are used for building these kayaks. Handmade kayaks are usually made up of wood sometimes wood strips are covered by fiberglass. If ocean kayaks are of skin on frame then main frame of kayak is covered by canvas, Dacron or some other type of fabric.
Ocean kayaks sometimes have steering gear in form or skegs or rudder. Usually rudders are attached at stern and operated using wires from cockpit. For beach landing these rudders are retractable. Basically skegs are straight blades which drop well in the stem of boat. These gears are there for smooth paddling when there is strong ocean wind.
Paddles used for ocean kayaks are different. There are three basic types of paddles for ocean kayaks are seen, European paddles, Greenland paddles and wing paddles.
Ocean kayaks are now used worldwide for marine journeys, does not matter for long low they are used from few hours to many weeks; they are becoming more popular with passing years.