<p><b>Fig. 9 </b>  Compartments: watertight subdivision
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Ships are divided into compartments by walls called bulkheads. Access to these compartments is by doors or hatches, designed, when closed, to keep the compartment watertight.
<a href="//commons.wikimedia.org/wiki/User:Andy_Dingley" title="User:Andy Dingley">Andy Dingley</a> (scanner)
Scan from <cite class="book" style="font-style:normal"><i>by Authority of the </i> Lords Commissioners of the Admiralty (June 1943)      <i> A Seaman's Pocket-Book</i>, <a href="https://en.wikipedia.org/wiki/en:London" class="extiw" title="w:en:London"><span title="capital and largest city of the United Kingdom">London</span></a>:  <a href="https://en.wikipedia.org/wiki/HMSO" class="extiw" title="en:HMSO">HMSO</a>, pp. p. 11,fig. 9  <small></small></cite>