Harp Song played by Marina in Episode "Raptures of the Deep"...?

Hello to everyone.

I've ben watching Stingray since it was aired on TV when I was a child so I really love it, but just as much as almost every other Supermarionation show from Anderson's couple.

Now, in episode "Raptures from the Deep" (AFAIK 1x09), during Troy Tempest's (sort of) dream, Marina whose voice one can finally hear, plays a so sweet melody with her arp, upon Troy's request.
Now, that song… well… I'm in love with it since when I was a kid, I must admit!

I tried to find infos over the internet since many years, but nobody seems to know (or report) anything AT ALL about it.
That's why I am trying to ask here at IMdb, as well.

If there is one chance over a thousand I could buy the CD containing it, or to buy it online wherever thus to listen to it in a better form, I'd do it in a nanosecond!

Hope someone could help me in this search that started many years ago…
Thank you all.

Cheers,