Sunday, February 13, 2011


iPhone app soon available

Dr. Newell “Toby” Garfield is Director and Professor of Oceanography at the Romberg Tiburon Center, San Francisco State University (part of the California State University System). His organization has some assets that he’d like to offer to the organizers of the next America’s Cup.

Garfield’s team has developed technology to measure surface currents using shore-based radio Doppler remote sensors to map surface currents over a large area with sufficiently high temporal and spatial resolution.

For sailors, this means RTC can measure the whole area that America’s Cup Race Management (ACRM) has designated for the AC34 racecourse and provide current data at half hour intervals with a spatial resolution of 400 meters. With a few more antennae established at pivotal locations around the Bay, RTC hopes to bring that spatial resolution down to about 200 meters for even tighter near-time current measurement.

According to Garfield, in prior America’s Cup competition spatial variation of the currents did not play a significant role; in the open ocean like Valencia and Auckland the currents were spatially relatively constant. We know that on San Francisco Bay surface currents, waves and wind will likely be highly variable over the racecourse area during racing.

Currents near the Golden Gate can reach speeds of nearly 3 m/s (6 knots) while to the east the currents don’t usually exceed 1 m/s. During the tidal cycle strong current fronts migrate across the region, accompanied by changes in the waves, always posing significant challenge for sailors racing on the Bay.

“For the America’s Cup and for all sailors on the Bay, the goal is to compute the currents with minimal lag time and then develop projections for “real time” and short term forecasts,” Garfield said. “For someone not familiar with the Bay, it levels the playing field on what the current variability is across the Bay and will start showing people where these things are on an hourly basis right through the tidal cycle.”

Garfield doubts that anyone else has this kind of data to offer. “Anybody else that would give you the kind of resolution we’re getting would have to be using a model - this is our prediction based on the physics - most models wont be able to that. This is the equivalent of putting in a current meter every 200 meters on the whole racecourse which would be impossible.”

His team is working on an iPhone app as a mechanism to deliver the current information that Garfield anticipates will available in about a month. Presently, the only way to retrieve the data is from the RTC website but it is completely free to anyone who wants to use it.

Garfield concluded, “Because it’s a state-funded project there’s not a lot of direct benefit to RTC. Our goal is to create a demand for the information just to keep the funding in place to be able to continue providing this data which has important application for all Bay sailors.” For more information, visit

*NOTE: Garfield is hoping to garner interest from AC34 parties who would be interested in another RTC asset - its incredible waterfront facility located on the east side of Tiburon in Marin County. Just a short boat ride over to the San Francisco city front, RTC consists of 11 acres of flat land with deep water access - over 25 feet, a much sought after resource on the Bay and a perfect location for AC hospitality activities and other. For more info contact Toby Garfield at

Left pic: The 42 MHz Seasonde antenna located at Crissy Field.

Right pic: Green drops represent presently deployed HF radar systems on SF Bay; red crosses indicate locations of proposed additional systems.

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