This episode must have been reduced from a book since the title of the episode had nothing to do with the actual situation in the show. Perhaps, due to time restraints, portions were cut that would have revealed a more close relation to a 'watery witness' but had to be cut for TV sake as there was reference to a boat ride.
However, in this show we are treated to the gorgeous Fay Way playing Lorna Thomas, a movie star that has seen better days. She is set to begin a new movie produced by an old friend named Tony Raeburn. But just when things look like they are looking up, Ms Thomas gets a visit by a woman named Betty Clark advising that she is her daughter that was abandon years ago. Ms Thomas throws her out of the house right in front of her personal maid Harriet Snow.
Later Harriet goes to check on Ms Thomas only to find her dead. And with help from fingerprints it reveals that Betty Clark's husband, George, was in the house and also has jewelry in his car that belongs to Ms Thomas. Perry will be called in to swim against the current as he tries to find the true murderer.
This episode was a classic who-done-it as we get a show full of characters that had some motive for the killing. It will be near the end that Perry finds out that one witnesses made a slip-up in testimony. When he asks the reporter to read back part of the mornings testimony- the true person is exposed. And we get those three words, "I killed her", to end the show with satisfaction. Good watch