TNA podcast: Three generations of master mariners

Why at one time was it necessary to know about the duck-billed platypus to join the Royal Navy?
This presentation by master mariner Len Holder explores the maritime roots of his family starting with his great-great-grandfather. He discusses some of the key information sources for exploring merchant mariner careers weaving them in with the family stories.
http://media.nationalarchives.gov.uk/index.php/three-generations-of-master-mariners/