Rear Admiral William Schachte.
Bingo!!!!!!!
You have the right answer. Gardner was not on the Boston Whaler that night. Schachte was the OIC. Kerry was on training mission. The two enlisted guys on the boat (Zaldonis and Runyon) that night don't remember that Schachte was on there. But logic would dictate, you don't put a new officer on a training mission without an experienced officer being present. Schacte's call sign was Batman. Kerry's was Robin. POW!!!