Juan Codere has weighed in on this subject via email to me. He's given me permission to post this to the board, so the next couple of posts are our email correspondance.

Greg

Having just looked through your message board, I note there is a question relating to the interplay between the colloquial version of names and the official version.

Re Watterson, whatever the reasons for which it was translated (if it ever was cf perhaps norse influence at the time it was first recorded when the island was not at all universally anglophone, far from it), it would seem that Mac Water/MacWatter/ Mac Uaitéir just followed the natural tendency which prevailed in relation to all C, Q and K names irrespective of the fact that Watterson in the anglicised guise was gaining a foothold as the official version of the name. Various explanations as to why the name was translated are not very convincing since the number of English speakers was not very high at the relevant times and there were plenty of occurrences of Mc Water still around. So that side remains a bit of a mystery. That said, if Wattersons were always known in the spoken language as Koderes/Codheres/Coderes/Kodheres, the gaelic version of this anglo normand name, perhaps originating from Ireland, seemed to be fully alive.

If it can be accepted that the Mac Water version was pronounced with emphasis being placed on the end of the name ie mac Water (see Kneens?? book on surnames with a section on colloquial pronunciations when explainging Codhare) , when the mac became eroded, we would have imply retained C'water.
In the manx names book by Quilliam under the Qualtrough entries, we find Quatter which should perhaps be in the Watterson section beneath. On the basis of this exemple, the name in its late spoken gaelic form was recorded (at least once). For C'water to be pronounced Kodere, we have by way of comparison the popular pronunciation of Qualtrough (Colcheragh) where the "ua" sound seems to have been slurred over to produce and "o" sound.
I have the name Kodhere (manx passport) and the name Codere (on my French passport). I switched back to the manx version (I am 100% manx, for what that's worth). My son, born in 2001, is the first official Kodhere/Codere to be around for centuries.

Regards,
Juan Codere.