Tunnel under water surface (for <a href="https://en.wikipedia.org/wiki/route_diagram_template" class="extiw" title="w:route diagram template">route diagram template</a>)
<a href="//commons.wikimedia.org/wiki/User:Optimist_on_the_run" class="mw-redirect" title="User:Optimist on the run">Optimist on the run</a>
2007-07-20
Own work based on: <a href="//commons.wikimedia.org/wiki/File:BSicon_WTUNNEL1.svg" title="File:BSicon WTUNNEL1.svg">BSicon WTUNNEL1.svg</a>)