Christof (CStork) is talking about a Type V PFD that the outfitters use for their commercial rafting clients. The Type V PFDs have the pillow behind the head that keeps your head above water when unconscious and when new, can provide up to 25 lbs floatation and don't porovide very good upper body mobility. America's Cup is just one of many makers - Extrasport and Stearns, among others, also make Type V PFDs.
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse