This is the second story from St. John Publishing's Strange Terrors #6 (Jan.1953) that seems to be re-purposed from an earlier adventure tale. The lead characters in "Peril Haunts the Depths" wear what could easily pass for "cheapo" superhero union suits, so perhaps someone will be able to identify these guys if that's actually the case. The writer/artists on this feature are unknown.
That leaves two more eerie stories and one single page strip to go and you will have read the entirety of this golden age rarity. See you back tomorrow for more!