So you heard that there are big waves there at Mavericks. There certainly are and there are the people
gutsy enough to surf them. You've heard that it is a remote place of cold winds and green water and fog and
cliffs. The obvious question though is how is the diving around there? Well, it's special! This is the coast on
the outside of the San Francisco Peninsula. It is 100 miles of rugged windswept beauty between Santa
Cruz and the Golden Gate. There is a lot of potential for diving there with only a few minor drawbacks.
It is as beautiful and primeval under water as it is in the steep redwood covered mountains above the
shores. This is a place of cool sea mists in rocky coves. It is a place where the beaches have few
Mavericks is just around the side of Pillar Point which is the northern corner of Halfmoon Bay. The town of Halfmoon Bay is a neat place and is divided from the Bay Area by a nasty enough mountain road that it is not useful for commuters even though it is not so far. That has kept the growth of the town under some kind of control. Go to the fishing docks. You can find something to eat. Local tuna, salmon and crab are common meals there. There is a big beach that is easy to get to. If you are on a bicycle, you really notice the big grade north of town on Hiway 1.
As everywhere, The diving is determined by weather. That can mean winds. Go diving in the morning. Afternoon weather is just going to have more wind. I used to use a method for judging wind speed for diving. Iceplant is a succulent common to the coast. I would take a piece of iceplant and throw it off the cliff (probably not good for the plant). It is a heavy dense plant and isn't easily blown around by the wind. If it fell down the cliff, the wind was OK for diving. If it came back and hit me in the face, maybe. It depends on how hard up I was to dive. If it just sailed over my head, forget it.
Now the waves. The waves are another part of the diving. There is a reason the big name surfers go there. These waves may be coming from Alaska or Japan. No matter what, they've had a long time to get big. Even on a calm day, expect sleeper waves at least double the height of a normal set. Even on a mild day, bring your advanced wave, current and rock entry skills.
Oh, yah. One other thing about the wildlife there. It's about the dead middle of the coast that is called the White Triangle or the Red Triangle by the more melodramatic amongst us. This is the place of the landlord. You know... Whitey. But don't worry about it. If they bite you, it's probably only a mistake. Just watch the seals. They know... Usually.
Now there is something else unique about the diving conditions there, related to geology. The geology of Half Moon Bay is circles. The rocks are metamorphic and so have changed from sand to rock, but the patterns in the rocks are circles. It happens some places in the world, but Halfmoon Bay is about the best example of it. Go to the tide pools a bit south of the bay and you will see little circles down to perhaps 5 feet and you will see big circles up to 100 yards. I think they get far larger. They are very unique and interesting. The other unique point about geology and diving Halfmoon Bay is those metamorphic rocks I mentioned. They are called mudstone, because as far as rocks go they are pretty soft. As a matter of fact, on some days it is very hard to tell where the water stops and the bottom begins. You can get blackout conditions at the bottom few feet. This especially true in spring during the plankton blooms. Be aware, 6 feet is pretty decent vis in that area.
Now for the boaters, I have a tip too. Halfmoon Bay is just that, a half moon shape that tucks nicely into the coastline. You would not believe the rock ridges running through that bay just under the water. The buoys mark the safe passage through the harbor. It is a path that leads far to the south side of the bay. One especially large wicked rocky ridge crosses the north side of the bay like a barrier wall of rock teeth. Most of it is under water, but there are also a lot of rocks that come and go as the swell churns by. Some always show and are a rest for sea lions and seals. Obviously there are passages between them, but they are only for the very brave or the very foolhardy. Sensible folks go the long way around. The sharp rocks in the waves are intimidating, but have an incredible harsh beauty.
The best time to dive would generally be from June until the swells start again in October or November. Expect water temperatures mostly between 50 and 60 degrees.
So why would a person dive around Halfmoon Bay with conditions like that? Obviously, because it was there, I wanted to dive and who cares if it is cold rough sucko diving. Actually, I usually did my diving about 40 miles south at Pidgin Point where it was no better, but I did make a few dives there. They were nice sunny calm mornings. There are areas of the coast just south of the bay that can be gotten to without too much trouble. The rocks drop off the shore slowly. Because of the poor visibility. Everything can be a sudden encounter, whether it is to find some unusual starfish or bump into a Lingcod head to head as you explore down a crack. You may see anything. This cold water is nutrient rich and life is thick. Get on the bottom and try to get into cracks where the kelp has been worn off by wave movement. You are two eyeballs being thrust into a complicated adventure of sight. There are the sponges colored vivid orange, cobalt, sulfur and other colors. There are abalone, scallops, urchins, snails, clams, sea cucumbers, octopus and other invertebrates. The anemones come in assorted sizes up to huge and colors of intense green, gold and red. When I was in school there, I studied seaweeds. There is every assortment of red, green and brown algae, as well as other plants.
It is a place where you can actually go tide pool diving in calm conditions. This is free diving and allows you fantastic ability to get into the reef and see it. In shallow areas of say 2 to 10 feet on a very calm day at low tide, the waves will concentrate on the outer edge of the reef. Inside of those waves may be a large calm area of rocks and holes. Waves come through, but mostly they have spent their energy. You can swim through the channels between the rocks and go into the smaller holes that open up. You will find that each hole is like an aquarium with no limit on visibility (except rock). It seems that each hole you go into has a different main specie inhabiting it. One hole may be full of Patirina starfish, the next full of purple urchins and the next full of crabs. You can dive in these holes while substantial waves are just above you. The holes in the reef between rocks may be a few feet deep or the size of a van. You can pop up for air with your body still braced between rocks just below the surface. It is rough above, but calm below. Watching waves from underneath is fascinating.
As for Mavericks and Pillar Point itself, I never got to dive off that point, but I can tell you that on a calm day, not a common day, it would be a lot of fun if you are up for it. There are big rocks and deep cracks to hide life. You would probably see lots of large colorful anemones in a surgy place like that. It would be fun to dive on the outside slope of Mavericks and try to get a feel for the lay of the rocks that throws the deep water swell skyward to make such awesome waves. It would be cold and poor vis, perhaps rough, but well worth it for what you could see and the adventure that a dive there could be.
Even when the dive is over, it is not completely over. You go into shore and since it is calm you keep swimming in the shallows instead of walking out the last bit. Here you see that this is the best color of the day because the undimmed sunlight shines on the brilliant colors right in front of your eyes in the tidepool. You lay there in the still water and wonder why you went to the trouble to go deeper.