Anyone remember ..?

[um]

I recall seeing a movie on TV (more like a documentary) sometime from the early to mid 1970s. It was on a NY network station such as Channel 9 or 11 or maybe 5 ( in that order or likeliness) and the movie was in the afternoon when these such TV station often filled the airwaves with obscure or old or even hardly-known movies to pass time until other programming later in the day, and I recall the movie had words in it about searching for the Great Barrier Reef and the movie showed how a family consisting of a young couple ( hippie like) and their "flower-child-like" kids were going to the area of the world where there are Barrier Reef sharks. The movie must have been made in the late 1960s to the early 1970s or roughly. I tried looking this up in the internet but there are only other movies or documentaries or animated movies about the Barrier Reef but not exactly this movie-documentary.
Anyone recall this movie from this description? What is the name? Anyone know if it is available anywhere?

[Dude111]

Hmmmmmm nothing comes to mind........