On a Sunday in June this year we had a memorable trip in our local river. My kayaking buddy and I are probably classed as flatwater yakkers but we've had some rough rides out in our local Carquinez Straits (where the Sacramento River narrows before it joins the upper San Francisco Bay) that might classify as whitewater kayaking. Here is one incident that also can be called a close call.
Calm Before the Turmoil
Misty and I launched from the Ninth Street facility and headed west. The tide was low and still going down to a -1.4 level as forecast for our area. The winds were generally in our face and the water was somewhat shallow. As we headed farther west we could see areas of foamy and churning water. About 100 yards out from the Benicia State Park we slow paddled and observed the area. The water was churning heavily to our left, out towards the center of the Straits and somewhat less where we were.
The Crosswise Waves
As we turned towards the Benicia City shore the waves crested higher and came at us from a crosswise direction. We started to roller coaster up the crests and become air borne over the troughs. Water was coming up over our bows and my spray skirt was holding off lots of water. Misty was not using a skirt and taking in water. I was paddling hard to keep perpendicular to the waves while the waves, sometimes 2 and 3 feet high, were pushing at my stern. It was all we could do to keep our respective kayaks, my Acadia and Misty's Bayou, going into the waves. I got troughed once and thought I was going to go over but was able to paddle around into the wave. And just when it seemed these conditions would not stop, the waves lessened and disappeared as we got farther into the Southampton Cove area.
Calm After the Turmoil
We made it into the Southampton Cove area, where the water was only about a foot or so deep and we watched the storks and pelicans stroll by. It was very calming after our ride on the wild side, right Misty? We paddled back to the Ninth Street park and although some spots were wavy with following seas, they were not as serious as the waves we experienced near the State Park. After a snack break, we got wet again trying to launch into surf waves but that was just annoying fun unlike the more scary waves we went up against in mid Straits.
So, what does cause the waves to appear almost out of nowhere like they did for us?
My theory is a phenomena I call a "depth crest wave". We were on the edge of where the shallow water meets the very deep water of the ship channel and waves crested in this area similar to breakers on an island. But, there may be a more precise explanation out there. Anyone have a theory?