This is in regard to Peter Greenberg's article ("Some Ships's Doctors May Need to be Examined," Feb. 4). I do not mean to dispute his claims, but my wife and I had a much different experience with ship's doctors. Last November, on the third night out on the Sea Princess cruise from Singapore to Sydney, my wife suffered a heart attack. She was in the infirmary for three days while we were at sea, and received outstanding care. The treatment by the doctors was perfect. And the doctors had all necessary arrangements for my wife's transfer to the hospital on land well prepared.