I read and lovedddd this as a kid. In my memory it was mainly a book about psychically communicating with dolphins? I forgot about all the really lovely grief stuff, and I definitely forgot about the sub-lovely love square between a 15-year-old girl and 20-, 19-, and 17-year old boys?? oh well it was the 80s, what can you do.

https://www.frowl.org/worstbestsellers/episode-196-a-ring-of-endless-light