This entry covers the 1966 expansion of the Marine Boy series, which added 65 new episodes to the original run, bringing the total to 78 episodes. All 78 episodes were sold to the United States. In Japan, the series had a somewhat complicated broadcast history: initially only the first 36 episodes were shown, but eventually the full 78 episodes were aired. The 65 episodes included in this entry are part of that total, while the remaining 13 episodes belong to the Ganbare! Marine Kid series.