Spanish Marine Province of Caracas: presumably used between 1815 and 1819, is refers by Mr. Jaume Olle in his "Electronical Bulletin of Vexillology from Catalonia", Part: Historical flags / Venezuela -
Reus, Spain-Catalonia 1999. Mr. Peter Hans van den Muijzenberg, refers it to J.W Norie - J.S. Hobbs: Flaggen to aller seefahrenden Nationen, 1971 (first printing 1848). Until now, in Venezuela and Spain does not seem exist any specialized registry that guarantees its existence.
Own work based on:

https://www.fotw.info/flags/ve-hist2.html
Salvadoroff