I may be alone in this, but when I saw the title of the post, I hadn't the slightest clue what it might be about - maritime did not come to mind on seeing MARITIMER by itself, though it may be that just the capitals throw me off.

Unless the context was very clear and not being in the industry, I would think maritimer and mariner and sailor were all equivalent.

Also, as Faldage says, residents of the Maritime Provinces of Canada are called Maritimers - it's even made it into a dictionary
http://www.thefreedictionary.com/Maritimer

On the other hand, for a publication that is specific to the industry (Maritimer: A Journal for the Maritime Industry), it might (or might not) be a very clever title as they would have a different understanding of the word than the general populous. But they might assume you're also making a joke with "time" - Maritime Times, Maritime Weekly, The Mari"timer" - if you can see that.