SOLVED. Science Fiction. [s]

[Mel]

Beings have come to an isolated planet and to remain undiscovered destry thair spaceships by sinking them in an ocean where the continental drft will destroy them. One of them is made of disks, which can separate to give offspring. This race is aggresive and warlike, but this individual is friendly and empathic

[Lobstergirl, au gratin]

Mel, please add some plot details to your header (from what you've already written). Many group members only skim the headers quickly and click on the threads they think they can solve. The more details in your header the more quickly it can be spotted by the people who can help you solve the book.

We also need to know when you read it or when it was published.

Cover?
Author female or male?
For a particular age reader?

[Sue]

There is a query similar to this on Abebooks Booksleuth. I think this is possibly David Brin’s Uplift series, the trilogy starting with Brightness Reef.

[Andy]

I agree with Sue - this is Brin's "2nd Uplift Trilogy."

[Mel]

YES!!and thank you all for your help. This is indeed the one, I passed it over several times without realizain it.
Thank you all again.

[Kris]

Glad you found your book, Mel. Here's the link for the book - Brightness Reef by David Brin - Sue and Andy's find.