The National Library of Wales has made available Aberystwyth Shipping Records containing crew accounts and agreements (generally known as crew lists) and logbooks, together with associated papers and correspondence, 1856-1914, for 544 merchant vessels registered at the port of Aberystwyth, Cardiganshire.
There's a blog post from the NLW about the records with information that:
Whilst children from the age of 12 onwards are often listed as crew members, Evan Davies, 9 years old, from Llansanffraid, Cardiganshire, included in 1857 as a crew member on board the vessel Ellen (‘this being his first ship’), is surely the youngest crew member listed among the records.By coincidence this came to me on the same day as as an email from findmy past.co.uk about the company collection of merchant mariner records containing a record for 13 year-old deck boy Eric Abbott, and asking – could he be the youngest ever Merchant Navy Seaman?
Reading the NLW blog from Ottawa one can't help but reflect on how dynamic the organization seems compared to LAC, witness the most recent items of LAC News:
Major interruption of LAC computing services April 20, 2013
Launch of an improved order form for reproductions
Interruption of LAC Reproductions Services April 13, 2013