Mary, I have checked through some relevant threads, and it would appear that the song you are looking for is actually called "Sailor Home from the Sea" from a poem by Dorothy Hewett, with melody by Martyn Wyndham-Read. The Sangsters haven't recorded this either, although they did record another Wyndham-Read adaptation on their first CD ("Silence and Tears" by Lord Byron).

I further note that you said on the other thread that you heard the song sung by 2 men and 2 women, but I have to point out that there is only one male voice in the Sangsters, who are a trio !!

Best of luck with getting your Sangsters CD anyway, and I hope you manage to locate the group you heard on the radio.