The Humphreys designed Half Tonner Glafki III

Soon after her successful Half Ton Cup in 1979, Roller Coaster was purchased by the young Greek Ioannis Alafouzos, and as Glafki II she won the 1980 Aegean Rally, one of the more important Mediterranean regattas.

Meanwhile, Alafouzos and Humphreys were planning his next boat, Glafki III, which was built of composite epoxy in time for the 1981 Half Ton Cup in Poole. Glafki III finished third in the Worlds, just half a point behind the second boat, and on her return to Greece she became one of the dominant boats in home waters, winning the Aegean Rally on six consecutive occasions.