I still sigh in despair at the things that are unsaid here, and the ways that these worlds are NOT earthlike - we're talking water worlds again, and as I've long argued, although aquatic life is very likely on such a planet, yet it also unlikely that technological civilisation is possible on such a planet.

Dolphins, fish, squid, seaweed, green slime aplenty, but no radios, rockets, or computers. (IMHO).

Megadittos.

I think that it's very likely that there ARE lots and lots of Oceania planets, planets in a warm star zone covered by deep liquid oceans with NO land masses. Think about the universe and its prevalence of hydrogen and yes water, albeit mostly frozen in our solar system. Spectroscopy tells us that water is ubiquitous and can be eliminated by collisions (q.v. the moon's formation) but mostly it prevails.

Massive Oceania planets around M, K, G, F whatever stars. But as Nick laments no chance to becoime technological with no ability to harnes fire and run up the difficult technology learning curve. Possible intelligences, but no technological civilizations.