Kerry, sorry I haven't answered your message previously, but I only occasionally visit this site, these days, thanks to a massive amount of research work. Unfortunately, I would not be able to tell you about an Army/civilian controlled vessel, as I only have a listing of the deck logs for Naval commissioned vessels. Since there was no Union Naval vessel named the St. Maurice, there are, of course, no deck logs.
Additionally I would like to state that, despite Mr Brooke's kind words, I am no expert, nor do I know a lot about anything. I am constantly acquiring knowledge, through searches and perusal of documents, but there are many others who would have a much greater knowledge of the subject/s I am interested in.
Sorry I could not help you with this query.