Bringing a favorable wind to the Japanese sailing team Through analysis of tidal current data accumulated since the Beijing Olympics

February 12, 2021

Olympics, Paralympics and UTokyo
Research, education and legacies related to the sporting event
The Olympic and Paralympic Games will be held in Tokyo for the first time in more than half a century. The University of Tokyo, which is also located in the metropolis, has a long history of involvement with the Games. As you learn about UTokyo’s contributions to this global sporting event, the blue used in the Olympic and Paralympic emblem may very well start to take on the light blue hue of the University’s school color.

Bringing a favorable wind to the Japanese sailing team
Through analysis of tidal current data accumulated since the Beijing Olympics

Takuji Waseda
Professor, Graduate School of Frontier Sciences
The Amenbo observational vessel used for data collection and research work at Weymouth, U.K. The Acoustic Doppler Current Profiler (inside the circle) transmits a sound wave and measures currents by monitoring the frequency shift of waves coming back to it after being refracted through particles in the water.

In the Olympics, almost all types of wind-and-sails-driven boats short of large cruisers with cabins compete in the sailing events, previously known as yachting. The boats compete in races over a course marked out by buoys in the sea. Apart from the skill of the competitors, the most important factor determining the outcome is the wind. Almost as important, however, are the sea currents in the race area. Professor Takuji Waseda is a researcher in the Department of Ocean Technology, Policy, and Environment who constructs oceanographic data through his interdisciplinary studies linking ocean science and engineering. He has supported the Japanese sailing team since the Beijing Olympics by providing analyses and simulations of ocean currents.

At Weymouth. From left to right: Professor Takuji Waseda, Professor Kiyoshi Uzawa (now professor at Kanazawa Institute of Technology), Tomoya Nishida (then a student), Lecturer Ryota Wada (then a student), Assistant Professor Tsubasa Kodaira (then a student), and Coach Aiko Saito (JSF).

“Professor Kiyoshi Uzawa, who was at the Department of Environmental and Ocean Engineering in the Graduate School of Engineering, once competed in the Sailing World Championships and was a certified athlete for the Los Angeles Olympics. Around fall 2007, because of that connection, a coach from the Japanese national team approached my department with a request for support. The coach asked us if we could analyze in detail the currents in the seas around Qingdao, where the Beijing Games’ sailing events will be held. At that time, leading overseas teams were already conducting scientific analysis on the currents, but Japan had yet to work on it.”

Waseda was close to the America’s Cup project during his time at the Naval Architecture and Ocean Engineering department in the Faculty of Engineering. He played a central role in the new project to support the Japanese sailing team in the run-up to Beijing, with additional support from Uzawa. After running software-based simulations with students, they accompanied the team to their training camp for pre-Olympic events in July 2008, and collected marine data in the local seas for a week.

“The area off Qingdao is known for having generally weak winds, and there was a lot of talk about the importance of understanding local currents. For example, when the boats go around the buoys, the crew is free to choose whether to take it from the right or left, and boats that choose a route that enables them to use the currents will have an advantage. This is particularly true when winds are weak.”

Saori Mizuishi (rightmost/first year master’s degree student) is a member of both the Waseda Lab and the University of Tokyo Sailing Team. In July 2019, she took part in the 30th Summer Universiade, placing eighth.

The currents in the seas around Qingdao are strongly influenced by the tides of the nearby Yellow Sea. To make use of the scientific understanding gained from the analysis of the currents, Waseda’s team drew up an easy-to-understand current chart on the course area having 2km in radius and being divided into four quadrants. The chart was put in waterproof pouches and become an indispensable part of the kit the crew carried with them in training. At the next Olympics in London in 2012, the team started collecting data at Weymouth, the venue for the sailing events, as early as summer 2009. This decision was taken after a review of the performance in Beijing, where the team felt they had waited too late to start collecting data and had missed the opportunity to measure currents at the time of year when the actual races would be held. Despite starting earlier, however, the team failed to bring home a medal from Beijing or London.

“Of course, the tides are not the only factor affecting the outcome; even so, it was disappointing. My experiences at those two Games taught me that there is a difference between scientific accuracy and the kind of information that the competitors want. As researchers, we are always looking for more accurate data, but the boat crews want to know what they should do in a race situation. It’s important to have coaches who can process the information in a way that suits the needs of the crew and translate it into terms they can use.”

In the lead-up to the 2020 Olympics in Japan, Waseda has been working with the Japan Sailing Federation (JSF) as a member of the technical support staff. He has spent two years collecting observation data at the Enoshima Yacht Harbor where the events will be held, building up data and factoring in the local stormy currents that can occur suddenly in the area under the influence of the topography of Sagami Bay and the Kuroshio warm ocean currents. After many years of collaboration with the coaching staff, their teamwork is closer than ever. Perhaps the 2020 Olympics will prove the “third time’s the charm” for Waseda and the Japanese sailing team. Please keep an eye on how the sailing competitors perform in the 2020 Olympics.

A grid-based current analysis of the competition area at Weymouth (75.6 x 71.5 km), where sailing events at the London Olympics were held.

* This article was originally printed in Tansei 40 (Japanese language only). All information in this article is as of March 2020.

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