Sea Horse Pittsburgh

In the beginning of 1950s dive clubs and spearfishing clubs were starting to form, and their activities were reported in the magazine The Skin Diver magazine. It was very expensive to purchase an Aqua Lung set, so the club members started helping each other to modifying the Oxygen Diluter Regulator to built their diving equipments.

When magazine Popular Science published a cover story titled "Build Your Own Diving Lung" in its July 1953 issue, it accelerated the race to customize the Diluter regulator. This has also led companies to develop diving units on a commercial level for the emerging market.

In 1952, The Dive-Craft Industries of Pittsburh, Pa was established and bulit their Diluters as "Sea Horse Diving Lungs" with single and twin tanks. DiveCraft later became Diving Industries, of Pittsburgh, PA. Probably the most successful company manufacturing and selling a converted oxygen regulator for SCUBA.

The Sea Horse regulators and sets (42 cubic  foot single or twin tank)  were marketed  directly to the public  all over the world, and successfully competed with Aqua Lung, Desco, Scott Aviation, and others well into 1957. Dive-Craft (Diving Industries) did not put serial numbers in their regulator or sets. 

Reference: 

1. The Journal of Diving History Spring 2011, Volume 19, Issue 2, Number 67 - Ed LaRochelle

2. Sea Horse Catalogs