| 摘要 |
<p>There is provided an oar for use in rowing comprising a shaft (5); a handle (1), provided to a first end of said shaft; and a blade (6), provided to a second end of said shaft. The shaft comprises a surface discontinuity (10a) along at least part of its length such that when the shaft and said surface discontinuity make forward contact with the airflow, a turbulent boundary layer is created there behind.</p> |
