The first use of wireless in the rescue of an American ship was in 1905. Relief Ship No. 58, a light ship, was in trouble off the coast of Nantucket. The operator sent "HELP" in International Morse and American Morse. This was before the use of SOS which started in 1906. A Naval Radio Station in Rhode Island answered the "HELP" call.1
The December 11, 1905 newspaper, "The World" reported the following; On December 10, 1905, during heavy gale, while relieving Nantucket LV 66 , Lightship No. 58 developed a serious leak in the fire-room compartment. Pump suctions clogged repeatedly and distress messages were sent by radio to Newport Naval Station (RI). Rising water eventually extinguished boiler furnaces and ship was then bailed by hand for 24 hours. The USLHS Tender Azalea responded, arriving in the early morning of December 11 and started towing the lightship. Heavy cross seas hindered the operation and about four hours later, lightship signaled "must abandon". The crew was safely taken aboard Azalea and 10 minutes later LV 58, listing heavily to starboard, went down by the stern in 25 fathoms about 18 miles NW of the station. 2
1 The Telegraph Office Magazine, Volume II, Issue 1, "'SOS,' 'CQD' and the History of Maritime Distress Calls"
2 Lightships - Light Vessels