<iframe width="580" height="385" src="https://www.youtube.com/embed/tox8IpUcOhw" frameborder="0" allowfullscreen></iframe> <br>The US and UK could no longer afford to lose any more vessels transporting valuable assets for the war effort. In their desperation to avoid more U-boat attacks, ... <br><a href="https://www.youtube.com/watch?v=tox8IpUcOhw">source</a>