The Deep Sea (Dave Fearless) series.
This adventure series features a character named Dave Fearless. In book form it was initially published as the Deep Sea series.
1. The Rival Ocean Divers; or, the Search for a Sunken Treasure (Stitt, 1905)
2. The Cruise of the Treasure Ship; or, The Castaways of Floating Island (Mershon, 1906)
3. Adrift on the Pacific; or, The Secret of the Island Cave (Grosset & Dunlap, 1908)
These three volumes were joined with another “Roy Rockwood” story, Jack North’s Treasure Hunt (Chatterton-Peck, 1907), to be advertised as the Sea-Treasure series.
Later still the three Dave Fearless titles were published by Sully in 1918 with new titles that used the character name in the main title and using the old title as a subtitle.
1. Dave Fearless after a Sunken Treasure; or, The Rival Ocean Divers (Sully, 1918)
2. Dave Fearless on a Floating Island; or, The Cruise of the Treasure Ship (Sully, 1918)
3. Dave Fearless and the Cave of Mystery; or, Adrift on the Pacific (Sully, 1918)
In 1926 these stories were reprinted as thick pulp paperbacks for newsstands by Garden City. A dozen new stories were added with volumes written by Howard R. Garis and Leslie McFarlane (as noted in his memoir, Ghost of the Hardy Boys (Methuen, 1976)).
The first volume, The Rival Ocean Divers, was first published as a serial in the weekly story paper Golden Hours (5 Jan 1901 — 23 Feb 1901). It was personally written by Edward Stratemeyer. This is one of two series that started with Stratemeyer’s personal writings and continued as a Syndicate produced series.
As he noted in his preface, he was partly inspired by the real dredging discoveries of a U.S. Fish Commission ship Albatross. As Jules Verne did some three decades earlier, Stratemeyer took the findings of a scientific expedition and mentioned the sea life in a fiction story. Verne did so in Twenty Thousand Leagues Under the Seas (1870, 1872) with the fictional submarine Nautilus. Dave Fearless met some of the creatures found by the Albatross in a deep-sea diving suit.
The other two volumes were ghostwritten by Chicago dime novel author and series book writer Weldon J. Cobb from Stratemeyer’s outlines.