Representing Ao Chalong Yacht Club, Duncanson's 7.5 metre-long Kingdom Property boat gave him more than a 20-second lead to take the top spot over runner-up Chris Way on the final day of racing.
Duncanson's (who also won in 2002, 2008, and 2010) win was significant in that the event called for all sailors to race in almost identical boats – the Platu 25 class.
Meanwhile, local Thai sailors Sarawutt Kunhak (38th), Cartoon Jundet (40th) and Thanakon Macfildoc (59th) all went well in Division A of the Thailand Optimist Nationals, an event for children up to age 15, while Phawat Phongguilai and Pongpech Taokrathok (11th and 23rd, respectively) both placed in Division B of the competition.
All five sailors represented the Phuket Youth Sailing Club and are from Phuket Sunshine Village, an orphanage for underprivileged children.