I’m never quite sure if it’s Màraig or Maaruig or even Mhàraig. You see all of them in use with the Ordnance Survey using Maraig for the township and Mharaig for the Loch and geographical features. I love this quirkiness and can envisage a Victorian surveyor banging a blackhouse door asking ”Where exactly are we my good woman – and how do you spell that?”
In Mike Parker’s highly recommended Map Addict, about his life-long obsession with the Ordnance Survey, he reproduces a wonderful passage from the instructions provided to surveyors in the OS Field Guide 1905:
For names generally the following are the best individual authorities, and should be taken in the order given: Owners of property: estate agents: clergymen: postmasters and schoolmasters, if they have been some time in the district; rate collectors; road surveyors; borough and county surveyors; gentlemen residing in the district; Local Government Board Orders; local histories; good directories …..Respectable inhabitants of some position should be consulted. Small farmers or cottagers are not to be depended on, even for the names of the places they occupy, especially as to the spelling, but a well-educated and intelligent occupier is, of course, a good authority.

Oh! Oh! Oh! Please Sir! Please Sir! I can answer that! My Gaelic lessons may be useful after all.
Màraig and Mhàraig are the same, it’s just that Mhàraig is aspirated to make it feminine as when it’s being used to refer to certain geological features that are feminine in nature.
Maaruig would appear to be a phonetic spelling of Màraig as à is a long drawn out a so a double a is a reasonable approximation in English.
And your vision of a Victorian surveyor banging on doors and asking that very question isn’t that far from the truth.
I think that reply deserves house points Tony.
You are in one of my favourite territories with this particular topic!:
http://direcleit.blogspot.com/2010/09/letters-from-alexander-carmichael-to.html
http://direcleit.blogspot.com/2010/08/togail-tir-marking-time.html
http://direcleit.blogspot.com/2011/01/placenames-revisited.html
And I think this 1886 chart offers ‘Mharuig’ as another alternative, courtesy of whichever one of the 8 Hydrographic Surveyors to whom it is credited was responsible:
http://maps.nls.uk/coasts/view-admiralty/?id=1215&zoom=6&lat=11102.5&lon=5993&layers=B
Peter
The origin of place names is a fascinating subject indeed. I particularly like it when local place names contradict the official version. I see that the autocratic park authorities at Loch Lomond had recently decided that they were free to rename features in and around the loch as they saw fit…
http://www.guardian.co.uk/uk/2011/mar/09/loch-lomond-chart-withdrawn
What I find particularly annoying about this is the fact that Captain Otter (and all the other Hydrographic Surveyors of the day such as Lieutenant FWL Thomas) took great pride in ensuring the accuracy of their charts especially with regard to the names of the features that they recorded.
He and his colleagues would, I am sure, be horrified at names being misused in this way.
Peter