Captain Compass was one of many features that Detective Comics had over the years. He originally appeared in issues of Star Spangled Comics, starting in #83. He bumped Robotman from that book, and that feature moved over to Detective, starting with #138.
Mark Compass wasn't really a captain; rather he was a trouble-shooter/house detective, initially sailing on the SS Nautilus, and later roving on various vessels of the Penny Steamship Lines. He lasted in Star Spangled until the very last issue of that title, #130, after which the book was converted into Star Spangled War Stories.
With no place to call a home, Captain Compass was assigned to Detective Comics starting with #203, where, ironically enough, he once again bumped Robotman out of a slot, ending that long-running feature.
Captain Compass was a decent detective, although like many in the comics he depended on eavesdropping:
And his fists: