An "ebb tide" means the water is draining back out of the Bay, while a "flood tide" means the water is flooding into the Bay. When the tide is flowing rapidly at times like this, there are places, usually created by the topology, where "tidal races" or "tidal rips" occur. These are places where the water speeds up going over bumps or around islands and rises up into noisy standing waves. Wind blown waves contribute to tidal races and were predicted to produce six foot standing waves in Raccoon Strait and at Yellow Bluff in San Francisco Bay this Sunday. I have seen tidal races several times before, and wisely chose to avoid a spot of water that was doing something strange that I didn't understand. But apparently I have been missing out, because other kayakers go out of their way to get into tidal rips for the fun of it. There was a BASK initiated trip to go play in toady's five knot ebb tide, and I decided to come along.
Four of us showed up at the put-in spot next to San Quentin State Prison. It had rained a little earlier in the morning, but by noon the sun came out and it turned into a sunny day on the Bay. We paddled straight out past the markers for the ferry boat channel, in the hopes of catching the tidal current sooner and getting it to help carry us along. There was very little wind, and with all the water moving with us it was difficult to tell that we were actually moving along at a good clip. I watched a buoy far across the bay and was surprised to see it (apparently) swimming rapidly past Oakland in the distance, indicating that I was actually drifting rapidly sideways. We paddled past one of the tall markers for the ferry channel, and it looked like the periscope tower of a submarine going upstream.
I had my spandex wetsuit liner on, but because of the warm sun I left my nylon windbreaker stowed inside the kayak. I found that the cooling effect of the spandex sleeves could be used to good advantage on a warm sunny day. Just a little water splashed on my long sleeves did an excellent job of cooling me down and I was able to maintain a comfortable temperature sitting in the sun in my 7 mm black insulated pants all afternoon. Later in the evening when the sun went behind a bluff the spandex sleeves were too cold. However, putting on the windbreaker warmed me back up nicely.
We paddled directly into Raccoon Strait, the narrow strip of water between Angel Island and the Tiburon Peninsula. There was a strong current through here, but not the raging torrent I expected. However, when we were most of the way through the strait, we saw some other kayakers playing in some dancing water ahead of us. This dancing water approached us faster than we were traveling and turned into a field of noisy waves, the rip current at last. We plowed through the first few larger waves, perhaps a meter tall, then let the current help push us a few hundred meters through the following smaller waves. Then we turned around and surfed the waves back against the current. I could have been fooled by the play of the current, but I'm reasonably convinced that the edge of this rip was traveling up the strait. When I tried to surf all the way back over the first few waves, it took longer and longer than I expected to catch up with them. Eventually, I gave up rather than get too far away from the other kayakers.
The maximum ebb current was supposed to happen in another hour, so we hurried around the southwest corner of Angel Island to stop for lunch. We landed on a beach on the south side of the island that was in the lee of the tidal currents. Instead of going back to Raccoon Strait after lunch, we crossed directly over to Yellow Bluff on the Marin side of the Bay. The water in front of Yellow Bluff is reported to have really good tidal rip currents. The currents from Raccoon Strait and Richardson Bay combine together here trying to get out the narrow mouth of San Francisco Bay. Unfortunately these turned out to be a bit of a disappointment this time. With no wind on this day, the waves in this rip were smaller than the ones in Raccoon Strait. Not the two meter standing waves some of the kayakers were hoping for. I also suspect that we were a little bit late for the maximum ebb, or it happened a little earlier than expected.
One nice thing about the Yellow Bluff rip was the eddy current. The main current went around the bluff and caused an eddy to run backwards along the shore. You could run down through the rough center part of the current, then relax in the eddy and get an almost free ride back to run the rapids again, and again, and again. In fact, this is just what everyone else seemed happy to do. There was talk of waiting for sunset, and even waiting for the moon to come up. I guess I'm used to a more exploratory mode of kayaking. After a few cycles I was ready to move on but everyone else kept going round and round. I tried paddling against the current, which was surprisingly easy with the waves to help. I tried sitting sideways in the current, to see if the waves could push me upstream when I presented a wide cross section. The kayak did seem to sit in one place sideways, neither running down stream nor surfing upstream.
Eventually the current calmed down and wasn't as much fun as when we started. Everyone paddled around the point into Horseshoe cove. The sun was already down and the moon did come up while we were stowing our equipment and changing out of our wetsuits. The water looked so calm and inviting by moonlight I was sorry we hadn't waited out on the water for the moon to rise after all.