Irish troops had served in the armed forces of the Spanish empire for hundreds of years by the time of the American Revolution. According to the Wikipedia entry for "Flight of the Wild Geese","...the first Irish troops to serve as a unit for a continental power formed an Irish regiment in the Spanish Army of Flanders in the Eighty Years' War in the 1580s". As more and more Gaelic Irish noblemen and their supporters and dependents fled the English in their home country, the foreign regiments began to be formed in other countries with large Irish expatriate populations in them.
Evidently, the first Irish regiment formed in the Spanish army was the Regiment Ultonia whose service in the Spanish cause dates back to 1597. It went through several names alterations until finally settling on the Regiment Ultonia. Eventually, it would be joined by the Regiment Hibernia and Regiment Irlanda. Thus, was formed the Irish Brigade of the Spanish Army. According to the Wikipedia entry for "Regiment of Hibernia", "Swiss, Germans, Italians and Walloons were recruited but the Spanish were particularly keen to engage Irishmen because of their reputation as soldiers". The regiments of the Irish Brigade of the Spanish Army would serve in Europe but, would serve mostly in the Americas during the American Revolution. The Regiment Irlanda was stationed in Havana from 1770-1771. The Regiment Ultonia was stationed in Mexico from 1768-1771. The Regiment Hibernia seems to have had the greatest involvement in the Americas during the American Revolution. It served first in Brazil in 1777 and later, Jamaica in 1780. It also participated in the Battle of Pensacola in 1781, resulting in the capture of East Florida from the British. After wards, the Regiment Hibernia served in the invasion of Honduras in 1782-1783.
Any of these military units, except possibly the Regiment Hibernia, could have been stationed in the vicinity of Corunna, Spain while the frigate South Carolina was moored there from September 24 - October 17, 1781. Dr. Lewis's work, Neptune's Militia, page 44, it states that, "he (Commodore Gillon) also recruited in Corunna, accepting aboard several Irish deserters from nearby Spanish regiments. The Commodore's willingness to sign on such types did not endear him to Spanish army officers in Corunna..."
All of the above posted lists of men who served or took passage on board the frigate South Carolina have been collected from Dr. Lewis's work, Neptune's Militia, "Appendix: Crew and Marines of the South Carolina", pages 135-170. This list have always provided names of individuals who belong to one group or another that was under study. Unfortunately, no list of this nature exists for the Irishmen of the Spanish Irish Brigade within Dr. Lewis's work. There is no one included on the list whose "position" states that he was a soldier form either one of the Irish regiments or a member of the Irish Brigade. Only a single entry under the "position" heading gives any type of hint that a man may have been a member of an Irish regiment who had been recruited by Commodore Gillon in Corunna, Spain for service on board the frigate South Carolina. In Dr. Lewis's work, Neptune's Militia, "Appendix: Crew and Marines of the South Carolina", page 148, there is a name entry of "Gamindez, -------" whose position listing is simply "Spaniard". There is no entry for his first name and his position on board the frigate South Carolina is listed as his nationality. This is only a supposition on the part of this blog writer. This individual could have been signed on board the frigate at any point, either before or after the period the frigate spent in Corunna, Spain. In the same way, there could be any number of Irishmen deserters from Spanish regiments contained in Dr. Lewis's appendix who are only listed by their names and not by the position they occupied on board the frigate South Carolina. There are many names included on the list that have no "position" cited after their listing.