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1·Its bodies in the sub water are apt to contact with the obstacles of the seabed because of its special character of sea gauge, consequently, causes ship grounding.

由于该型船特有的吃水特性，其深置于水中的潜体极易与海底障碍物发生接触，从而引起船舶搁浅。

2·First, the defmation and status of height datums is introduced and some problems on the local height datums established by the mean sea level, which is defined by the tide gauge data, are discussed.

首先介绍了高程基准的定义与现状，指出了用验潮站长期平均海平面建立局部高程基准所存在的问题；