Good news! I have recently consolidated Sea of Gold, Dark Ocean and Black Reef into The Angus McKinnon Thrillers: A Trilogy.
All three e-books are now available on Amazon as one competitively priced box-set.
Here are the principal links:
Amazon UK: https://amzn.to/2lZ4xYg
Amazon.com: https://amzn.to/2lWhtOt
Amazon Canada: https://amzn.to/2ks5o3e
Amazon Australia: https://amzn.to/2lZ5ik4