For those who know the complex tides and currents of San Francisco Bay, it comes as no surprise that things can be submerged in those waters for weeks or months before coming to the surface or the shore.
Richard Jepsen, chief executive officer for Berkeley Marina-based OCSC sailing school and a longtime bay sailor, is one of those people.
Jepsen, who helped create his school's training program, said the bay is a "unique body of water" in this region because of the massive flows that move in and out each day.
He said the entire bay is a study in fluid dynamics, with its contours and currents creating complicated patterns. Jepsen said even those complex patterns can change depending on the phase of the moon, spring runoff, wind direction and rain.
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From late December until just last week, he said, conditions on the bay had been relatively mild. "But the last 2 1/2 days, the wind has been blowing very hard from the west into Berkeley," Jepsen said Monday night.
With the shallow water -- about 6 feet or less in many places -- from the Berkeley Marina north to Richmond, Jepsen said secondary currents and circular flows can hold objects in the area.
It might take something like the recent storms to drive those items on shore, he added.
In late December, authorities went to the Berkeley Marina to investigate Scott Peterson's claim that he was fishing on the day that his wife, Laci, disappeared. The couple live in Modesto. Teams, including dogs and scuba divers, searched the bay and shoreline in January. The search extended to the waters around Brooks Island, where Peterson says he went fishing on Dec. 24.
While many might assume that objects in the bay eventually wash out to sea, Jepsen said that's often not the case. With all the islands and shoreline in and around the bay, he said, objects can turn up in any number of places.