(I've done a search for this, but there were pages of results, and it didn't seem to be the name of a thread, and I'm lazy. Sorry if it's been posted before.)
I've just recently got my hands on Marvel Comics Presents #46, and one of the stories is a Namor short.
It opens with him searching the North Atlantic. A couple of pages later, you find out he's searching for Marrina's hatchlings, which it mentions again explicitly.

So, not quite an appearance, but a mention.

Big caveat, I'm afraid: The story is one of the worst-written I've ever read.