Assessment of action in the upper part of the body on upwind dinghy sailing performance using a differential GPS

In competitive sailing where a race course is marked out by anchored floats on the sea surface, close-hauled, sailing, a technique for sailing upwind, accounts for about 60% of total race time. While sailing close-hauled, waves from the upwind direction cause the boat to slow down, and in order to minimize deceleration, the sailor leans the upper body backward. The present study investigated the effects on boat speed of the posterior leaning of the upper body while sailing close-hauled. Subjects were six male competitive sailors, and the study was conducted using an international Laser class single-person dinghy. The study was conducted in a hike out condition with wind speeds of 5-7 m/s with or without the upper body leaning. Boat speed was measured using D-GPS (20 Hz, Hemisphere), and a digital camera was used to capture the movements of the sailor in the dinghy. In data analysis, an average speed per two-minute period was used to calculate deceleration based on the maximum and minimum velocities while going over waves. The results showed no significant differences in average velocity with or without the upper ody leaning while riding in the left or right side of the boat. However, for an expert sailor, the upper body leaning significantly increased boat velocity. No significant differences were seen in deceleration with respect to the upper body leaning. The results suggest that for top-level competitive sailors, the upper body leaning is important and is a factor that affects boat speed.
© Copyright 2008 1st International Scientific Conference of Aquatic Space Activities. Published by University of Tsukaba. All rights reserved.

Subjects: yachting movement analysis measuring procedure
Notations: technical and natural sciences technical sports
Tagging: Dinghy GPS
Published in: 1st International Scientific Conference of Aquatic Space Activities
Editors: T. Nomura, B. Ungerechts
Published: Tsukaba University of Tsukaba 2008
Pages: 104-109
Document types: congress proceedings
Language: English
Level: advanced