WDT-AM signed on December 22nd 1921 in Stapleton, Staten Island. It was owned by the Ship Owners' Radio Service and operated on 360 meters. It was an early marine radio station broadcasting tide and weather information. At the time this was not exactly a ground-breaking service. In 1910 the Ship Act was passed aka the "Act to Require Apparatus and Operators for Radio Communications on Certain Ocean Steamers" This law required certain types of ships, foreign and domestic, to carry and use radio at U.S. ports. This was the beginning of marine wireless law and WDT followed that by a decade. What's unique is that station operated in the civilian radio band and had an FCC license to do so.
But the station was a share-time operation with WOR and WJY. How can a station provide timely information when they only broadcast for a few hours a day? They can't. the station only existed for another two years. But that didn't stop the Ship Owners' Radio Service from expanding. A 1922 article from the Deseret News described 44 stations in their network:
"Forty-four ship radio stations operated and controlled by the Ship Owners' Radio Service increased the ship message rate from 4 cents to 8 cents per word for all classes of ship service, beginning July 1st. the radio ship stations owned by the Alaska Steamship Company, which are also owned by the Ship Owners' Radio Service, will not, however increase the present rate of 4 cents per word. "But that article clearly refers to a telegraph service. The radio station WDT was another animal entirely. It was housed and operated by the Premier Grand Piano Corporation in June of 1923 and managed by Vaughn DeLeath, who was (at least back then) a famous singer. I'd like to connect the dots between her career and Premier and WJZ but I got nada. DeLeath's career really only began in 1916, and she was performing live in New York on WJZ-AM by 1921. Then a trade magazine for Presto wrote similarly of her position in June that year:
"Miss Vaughn DeLeath, "The Original Radio Voice," managing director of Broadcasting Station WDT, made a very interesting and felicitous opening
address, welcoming the guests present and stressing the appropriateness of the linking of Station WDT with the Premier Grand Piano Corporation. Later on she participated in the program in her artistic manner."
An issue of the Pittsburgh similarly records her as WDT's managing director in August of 1923.
"The station W.D.T. is one of the most prominently known broadcasting depots in the east and is under the direction of Miss Vaugh De Leath. She is the first director to introduce an entire Negro program and she takes great pride in hosting of such entertainment for which she receives much commendation."
One source, Allmusic, inexplicably claims she was managing a low power radio network. I cannot corroborate this, nor the claims that she was running WJZ. On December 22, 1923, WDT signed off for the last time and sold of it's transmitter. A religious group led by Judge Joseph Frederick Rutherford bought the stations equipment to start their own station, WBBR... More here. Ultimately the Ship Owners' Radio Service appears to have been short lived. Their only other known venture is a Crystal Detector that was manufactured by the Wireless Specialty Co. It was called the Sorsinc Stand Alone Crystal Detector, and I'm told it was identical to the Wetmore-Savage crystal detectors made by the same manufacturer.I hear there are some rare catalogs out there too but I've not seen them personally.