Issue(s): Sub-Mariner #63
Cover Date: Jul 73
Title: "...And the seas shall explode!"
Credits:
Bill Everett - Plot
Steve Gerber - Script
Sam Kweskin - Penciler
Syd Shores - Inker

Review/plot:
Doctor Hydro seemingly died last issue, but it turns out he's able to come back for one more scheme involving an out-of-control volcano.

Hydro now has the ability to turn to gas, so Namor sucks him up and places him into an airtight container, where he is sure to suffocate to death.

This story was completed from a plot written by Bill Everett in his final days. But let's focus on a happier topic, like hydrocules!

In the Tales of Atlantis back-up, we see the Atlanteans standing around while their city crumbles around them.

Kamuu's girlfriend Zartra is killed by a Lemurian looking for vengeance on the Atlanteans, and Zartra takes out a gem that she keeps behind her eyepatch and puts it on the hilt of Kamuu's sword.

Then Atlantis sinks into the sea.

Quality Rating: C

Historical Significance Rating: 1

Chronological Placement Considerations: N/A

References: N/A

Crossover: N/A

Continuity Insert? N

My Reprint: N/A

The back-up does indeed tie right in with Gerber's stories in Man-Thing as I learned reading Super Mega.
I never had much awareness of this corner of the MU tho my first MTU referenced the Lizard People. Was Kull developed out of this? I wonder what else grew out of this relatively obscure back-up series. Very popular topic in those days, Atlantis.

King Kull of Atlantis was created by Robert Howard in 1929, before Conan even. His first Marvel comic dates back to 1971, prior to this issue.