California surfing is a about the wave and catching it. Sometimes a rush hour is created when all the surfers get into a groove and find the same location optimal for surfing. There are a few near-collisions, occasional confrontations and some yelling. It's about skill, cooperation and courtesy.  It takes a bit of practice and knowledge to surf properly. If you are learning, you might consider going to a beginners section of the water so you don't tick off the professionals and competitive surfing regulars.

Waves are the movement of energy through water. The term wave refers to a series of vibrations, pulses or undulations in the water or some other medium. A wave is made up of a top, known as the crest, and a bottom, known as the trough. The horizontal distance between two successive crests is defined as the wavelength. The vertical distance between the crest and the trough is defined as the wave height.

Surfers in California tend to define wave height in terms of a person's body length. For example, 4-5 foot waves might be described as shoulder high, 7-8 foot waves as overhead, 10-12 foot waves as double-overhead. In Hawaii, waves are measured from the back of the wave, generally underestimating the wave size and height.

The speed of a wave is how far it moves in a given amount of time. Small waves tend to move slowly at a few knots (1 knot equals 1 nautical mile per hour). Medium-size waves may move at tens of knots; large waves move 30 - 50 knots and more. Tsunamis, which are the largest waves of all, can reach speeds up to 450 knots.

The period of a wave provides many important clues about surf conditions. The wave period is the time between successive crests. For example, if you stand on the end of a pier, start your stopwatch when a wave hits a fixed spot, and stop your stopwatch when the next wave hits that point, you will have measured the wave period. Long-period waves tend to be larger and stronger, while short-period waves are smaller and less energetic. By measuring the period of waves, surfers can get an idea of the swell to come within the next several hours, and determine whether different swells (waves that originated in different locations out at sea) are hitting the beach at the same time. Generally, longer period waves travel longer distances, have more energy, and create higher breakers on the shore.

Wave frequency is important to ocean engineers and architects who construct jetties, piers, and other man-made objects in or near the ocean. The wave frequency is defined as the number of waves passing a fixed point in a given amount of time. Again, taking a stopwatch, count the number of waves that pass a fixed point over a 30-second interval. Divide by 30 and you have the wave frequency, the number of waves that pass a point every second.

When the wind blows across the surface of the water, the water begins to ripple. These tiny ripples are called capillary waves. Factors that affect wave formation are: 1) wind speed; 2) wind duration, and 3) the fetch, which is defined as the area over which the wind blows.

The importance of the fetch can be realized when you consider that the biggest waves don't come from hurricanes, which have the fastest winds, but from large storm systems that blow over hundreds, possibly thousands of miles. Hurricanes are a local wave generator and will make waves over a small area, but for the most part, the really big waves that hit our beaches come from big storms in the Antarctic or the North Pacific Ocean.

How waves might be generated far out at sea: prevailing meteorological conditions during the winter in the northern hemisphere give rise to vast low pressure systems that generate lots of wind over vast areas of the ocean. Typically, these weather systems travel northwest to southeast, generating ocean swell, sometimes called groundswell. These winter storms may generate waves thousands of miles away, yet over a 24 hour day, a wave can cover 720 miles. Given a distance of roughly 3000 miles (for the sake of argument) between the North Pacific Ocean and Huntington Beach, these newly generated waves might be crashing on our shores in just over four days. More times than not, the best surfing in winter comes from that northwest swell.

What about summer surfing? Remember the big waves mentioned above? In our summer, winter storms brew in the southern hemisphere (because our summer is their winter). Storm systems traveling from southwest to northeast pack a mighty punch as they wreak havoc over a much larger ocean area than is even possible in our paltry northern Pacific Ocean. Take a look at a world map. More than 60% of the oceans reside in the southern hemisphere. The greater extent of the South Pacific Ocean allows larger fetch and creates even bigger swell than we find in the northern hemisphere. Thus, south swell tends to really get things rolling around here (i.e. the waves tend to be bigger when they come from the south).

Hurricanes and typhoons don't necessarily generate the largest waves, though the wind speeds in excess of 100 knots are possible in a hurricane or typhoon, the wind energy tends to be concentrated in a much smaller area than a typical weather system. In other words, the fetch for hurricanes and typhoons is smaller. While these powerhouses create incredible wind speeds, their action is limited to the specific areas in which they occur. Waves may be larger in the region of the storm for a limited time, but the large and consistent swell generated by long-fetch winds just doesn't occur.

One other feature in the formation of wave swell is worth noting. A given wind speed can only generate waves of a certain size. After a period of time, the waves get no bigger. In this case, the seas are said to be fully formed, the largest waves that can be created for a given wind speed are being created. Once formed, the swell is free to travel as far as it can, altered only by friction with the bottom or obstacles, such as islands or continents.

The generation of waves from the time the wind starts blowing to the time that fully-formed seas developed gives rise to a series of waves with different wave periods and speeds. Since the longer period waves tend to be faster, these waves move out ahead of the rest of the waves. For this reason, groups of wave trains develop. A wave train is a group of waves traveling at the same speed across the ocean. These waves, obviously, hit the beach at the same time and, hence, create the well-known phenomenon of wave sets.

Waves travel out from these storms for thousands of miles before they hit the California Beaches.