 The meeting with Coronado was never effected, though Alarcón reached the appointed place and left letters, which were soon afterwards discovered by Melchior Diaz, another explorer.Alarcón eventually sailed to the northern terminus of the Gulf of California and completed the explorations begun by Francisco de Ulloa the preceding year.During this voyage Alarcón proved to his satisfaction that no open-water passage existed between the Gulf of California and the South Sea.