Wrote this mid-April, 2004, upon the arrival of our first south swell of the season. Then the real south swell arrived the week of April 25th.

It's once again that time of year. Even if there's one or two additional pulses of NW swell headed our direction, the north Pacific is going to sleep. It will be a long slumbering hibernation, offering only inconsistent and modest wind swell for the surfers in Northern California until next autumn.

The great Southern Ocean has already come alive in its winter season of discontent. On weather maps and satellite images you can see vast roiling cycles of weather in the latitudes below Australia, Africa, and South America. These systems can spin for thousands of miles, unimpeded by any large land mass. In the process they uncoil long lines of marching swells that head north for lucky surfers in their path. This includes the western and southern shores of Oz, Indonesia, the islands of the Indian Ocean and the South Pacific. It also encompasses spots in the Northern Hemisphere like Maalea, the south shore of Oahu, mainland Mexico, Baja, Costa Rica, and, on occasion, the shores of California.

Here in DogLand hungry surfers eagerly await the rare but famous southern hemis that infrequently light our breaks with long peeling lines in the midst of a flat summer. So what's it take to fulfill this promise?

Wrote this mid-April, 2004, upon the arrival of our first south swell of the season. Then the real south swell arrived the week of April 25th.

It's once again that time of year. Even if there's one or two additional pulses of NW swell headed our direction, the north Pacific is going to sleep. It will be a long slumbering hibernation, offering only inconsistent and modest wind swell for the surfers in Northern California until next autumn.

The great Southern Ocean has already come alive in its winter season of discontent. On weather maps and satellite images you can see vast roiling cycles of weather in the latitudes below Australia, Africa, and South America. These systems can spin for thousands of miles, unimpeded by any large land mass. In the process they uncoil long lines of marching swells that head north for lucky surfers in their path. This includes the western and southern shores of Oz, Indonesia, the islands of the Indian Ocean and the South Pacific. It also encompasses spots in the Northern Hemisphere like Maalea, the south shore of Oahu, mainland Mexico, Baja, Costa Rica, and, on occasion, the shores of California.

Here in DogLand hungry surfers eagerly await the rare but famous southern hemis that infrequently light our breaks with long peeling lines in the midst of a flat summer. So what's it take to fulfill this promise?

All waves originate with wind disturbances on the ocean surface. Primo waves attributed to ground swell require stormy weather at sea. Most if not all of the ground-swell-producing storms occur during the winter season, which is roughly May through September in the southern hemisphere.

A puff of wind across the surface of a body of water will blow a small disturbance in that surface, a slight ruffle. The greater the wind, the greater the disturbance. If the wind blows for some amount of time, it will continue to dump energy into those ruffles. This will build the ruffles progressively larger, turning them into raw waves. If the wind blows in a consistent direction, it will drive the wave front along a specific vector, like cowboys herding cattle to the roundup.

Ground swell is generated by storms at sea that blow with sustained winds of many hours at high velocity in a consistent direction.

But there's more; the wave front has to be aimed your way. I've read that you can stand on the shores of New Zealand and aim your wave gun at Santa Cruz. When you pull the trigger your aim has to be accurate to less than a single degree of arc, otherwise you'll miss your target (which is my home break!) There are many waves generated at sea that will not make land anywhere near where you surf.

A storm at sea imparts energy into the surface of the ocean over a wide spectrum. This means there are waves of all descriptions jumbled together in or close to the bad weather. Think choppy, out of control ocean. There are short period high frequency waves, and longer period low frequency waves. They all start marching across the ocean as they propagate away from the storm front.

High frequency waves don't have as much inherent energy as low frequency waves. Traveling through the ocean bleeds energy, so that within a short time the high frequency chop dissipates and disappears. Only the low frequency waves have sufficient energy to make the long trek from Tahiti to Santa Cruz. But this is ok, since these are precisely the waves we love to ride. Traveling the Pacific cleans the surface of the choppy crappy waves, leaving only the underlying ground swell.

Waves of identical amplitude and period travel at identical speed. Over distance and time they segregate themselves from the rest of the waves manufactured by the storm. When they make landfall, they arrive as a collection of waves that are clones of one another. This is why waves come in sets. Each set is slightly different in amplitude and period, and hence has a slightly different rate of speed.

Even though long period waves have sufficient energy to travel thousands of miles, events can and do conspire to get in their way. Should they encounter sufficient headwind they will be depleted or even shrivel into nothing.

South swell in Santa Cruz requires storms in the southern ocean that blow with sustained winds of many hours, at high velocity, in a precisely aimed direction along a fetch that has little or no countervailing weather between the storm front and my home break.

Is it any wonder that south swell can be quite rare?

Even with such a swell in the water, the problem is not yet solved. Now we need to find a break with the correct exposure to this approaching swell. Some breaks receive only NW swell and miss south swell completely. Surf breaks N of Monterey, along the southern edge of the Monterey Bay are an example of this. On the other hand, Steamer Lane is famous for breaking with NW, W, and S swell. There are some reefs and coves in DogLand that only break on a south, never with NW swell.

Typical reef and point breaks require specific tides to go off. Too low and the reef is uncovered and dangerous; too high and the waves break upon the rocky shore. So during a period of south swell, at a break with the correct exposure, only certain times of the day during certain tides will be rideable.

Now we're almost there! Assuming there's a south swell in the water, your break has the right exposure, and you know the appropriate tides, you have one further task. You gotta be there! If you have a job, or if you have family obligations, or if your car is broken you won't be able to make the trip to the beach to enjoy the south swell.

Is it any wonder this is so rare? It's amazing we get to ride southern hemi waves at all!

Finally, here's the reward. Except for the couple of Steamer Lane pix, all the pictures in this column taken at dawn on Tuesday April 27 at a prime south swell spot in DogLand. Don't they just make you want to go surfing? Aren't you looking forward to the next south swell of the summer season? Will I see you out there? Aren't the typical summer NW wind swell waves incredibly lame compared to these waves?