Do I need to remove existing anodizing on a mast before appling etch primer prior to painting?

My yacht mast is covered with many small pit marks in the anodizing, they are not deep but plentiful. ie about 15~20mm apart and on one side of the mast more marked than the other, possibly due to acid rain or similar. I am therefore considering painting the mast. (re-anodizing would be prohibitively expensive)
The anodizing already looks pretty flat, therefore is it necessary to remove it all or only where it is still shiny, and should I flat it down all over with wetndry any way (though not necessarily to remove all the anodizing)?
The mast is 12 Metres in length and weighs around 200kgs. It is presently stored a Birdham Pool Marina near Chichester, West Sussex.