Hello James,
I lost my uncle John Reynolds in the second world war, he too served in the Merchant navy aboard a ship called the Socony. I have a full report of events leading up to his death including an extract from the Ships Log Book, a list of all his possessions, place of death (Atlantic Ocean) and last known address in Scotland.
If your James died in service you can obtain an extract of his Death Certificate from The Marine Register Book held in The General Register Office in Edinburgh. These deaths are not listed in the normal searchable Births Deaths & Marriages, only in the Marine Register Book, they will tell you if any other pages are available such as the Ships Log Book I was able to obtain. The fact his Death was not listed in normal BDM records threw me for years until I discovered they are treated separately.
Its a while since I looked but a good source of information is Warsailors.com which is searchable for Merchant Navy Personnel and Ships.
Good Luck
James Kerr.