Mineral spirits in a compass, ummm, that might explain why I have seen so many broken. No, that''s not it - it''s not spirits!!
Take Denr''s advice - buy a decent (expletive deleted) compass for the boat and tell her to get over it. Having a reliable compass is an asset always.
Besides, what kind of wife would not want to know the fastest route back to the bar after a day of sailing with her husband who has done nothing but remark all day about how well the new sail flies? Let HER buy some toys. I''m sure she''d love a mapping GPS unit. How big is your boat? What about an auto pilot? Have you ever let her thumb through a catalog, or do you just keep it in the head with you?