Founded in 1984 and has more than 100 members, from novice to top triathlete. The Dolphin combines cosiness with performance. The training sessions are given by several swimming trainers, a bicycle trainer and a walking trainer. Swimming training takes place throughout the year in the Sloterparkbad. The bike training sessions take place from April to September (summer time) and start (unless otherwise stated) at the Sloterparkbad. The running training sessions are given on the AAC athletics track.
De Dolfijn competes in the highest divisions in the Netherlands with various teams.