題組內容

(2)選用小比例海域海圖缺點為何？
 “Charts should be used with prudence: there are areas where the source data are old, incomplete or of poor quality. The mariner should use the largest scale appropriate for his particular purpose； apart from being the most detailed, the largest scales are usually correct first. When extensive new information (such as a new hydrographic survey) is received, some months must elapse before it can be fully incorporated in published charts. On small scale charts of ocean areas where hydrographic information is, in many cases, still sparse, charted shoals may be in error as regards, position, least depth and extent. Undiscovered dangers may exist, particularly away from well-established routes.”