The Tonight Show's boy Friday took time off to take a slow boat to Tahiti and he logs every day of it. With Downs as initiator, skipper, navigator, the rest of the crew was composed of a married couple, a retired electronics expert, a professional photographer and ""H.R.,"" the author's teenage son. They set sail from Fort Lauderdale on a cruise course that took them through Nassau and the Bahamas, Jamaica, Haiti and the Canal Zone, by Panama and Ecuador to the Galapagos and finally across the Pacific to their destination. En route they encountered storms, (at one point Downs was pitched overboard), radio trouble, problems with customs officials, and occasional breakdowns of such mainstays as the mainmast. They even discovered two men, marooned and living off goat meat on a deserted island. But events are circumnavigated by detail that could only be of possible interest to those planning a similar venture.