PERISCOP
... that the PERISCOP made it possible to retrieve live fish from over 2,000 m (6,600 ft) deep, despite the extreme pressure at that depth?
... that the <b id="mwAtg"><a href="./PERISCOP" id="mwAtk" rel="mw:WikiLink" title="PERISCOP">PERISCOP</a></b> made it possible to retrieve live fish from over <span about="#mwt22" data-mw='{"parts":[{"template":{"target":{"wt":"convert","href":"./Template:Convert"},"params":{"1":{"wt":"2000"},"2":{"wt":"m"},"abbr":{"wt":"on"}},"i":0}}]}' id="mwAto" typeof="mw:Transclusion">2,000</span><span about="#mwt22" typeof="mw:Entity"> </span><span about="#mwt22">m (6,600</span><span about="#mwt22" typeof="mw:Entity"> </span><span about="#mwt22">ft)</span> deep, despite the extreme pressure at that depth?