How DN might have hitched a ride
If Nyad were to connect herself to the boat, the mechanism would need to be out of the way, almost invisible, but easily retractable. I would guess that strong, clear fishing line would be implicated.
Here are three photos from Key West photographer Andy Newman (via CBS for the first two and Newman’s Facebook page for the third). In the first two, look for the white cord that hangs from the bottom right of the Secret banner, crosses the blue and white cable, then curves back in a V-shape to the boom. In the third photo, look in the upper right corner for the bottom of the V. I’ll explain more below.
If you zoom in and follow where the bottom of the V points, you can see a faint, broken white line in the water. That line would intersect with the streamer at about a 30-degree angle.
The second photo shows the V with a bit more slack but no visible line attached.
The third photo shows Nyad closer to the boat. The bottom of the V (top right) is closer too, a concurrence one might expect if Nyad and the V were connected, the line perhaps weighted like the streamer. Another faint white line descends from the V.
The idea is that when the current was behind Nyad, the line would lie slack. When the current flowed west to east, its usual direction, the line would keep her from revisiting the Bahamas.
Where does it connect to her body or suit? I have no idea and am open to suggestions.
One other bit of evidence: Nyad always veers right
Nyad has trouble swimming straight, hence the streamer. A former Nyad crew member told me that Diana usually veers both right and left. However, the logs from the 2013 swim, as well as an account from another member of the crew, only mention Nyad veering right.
That’s exactly what you’d expect if a boat headed north was towing her through a current headed east. Here are the citations:
Shift 5 (McVeigh):
…[Sat.] 9 pm shift has started…
Very easy for Diana to drift away from boat, kayakers have a tough job keeping her close to Voyager
Mon. 1:37 am (Hinkle)
Diana is always veering right, away from the boat and many voices direct her back to the light and the boat. More confusion than I’ve witnessed before. Everyone constantly bidding her to swim toward the red rope light and nearer the boat.
Mon. 4:45 am (Hinkle)
…Lots of encouragement from kayakers trying to keep her on course. “Go left Diana, swim to the light.”
For some reason, she swims to the right and she must return to the boat on her left to stay on course…
From John Duke, one of the captains:
Diana’s course towards the end of the swim became a constant battle to keep her directed towards Smathers Beach in Key West. She would slowly veer clockwise. THE XTREME DREAM TEAM: A RECORD BREAKING OPERATION
Nyad knew the potential of a tow rope. In her first memoir, Other Shores, she lists the rules of a 1975 race in Argentina:
The swimmer must wear only regulation suit, cap, goggles and grease. The swimmer must swim to the side of his boat, not behind it. (Greta Andersen was once passed in a race in the Nile by an Egyptian with a wide grin on his face; he had a tight grip on a rope tied to the back of his boat, and was eating a banana.) The swimmer may not at any time touch the boat, the shore or another person. (p. 35)
The boom Nyad used for her directional streamer gave her something to swim behind. I include the quote’s last sentence for a touch of added irony.
Testing one, two, three, four:
2013 — leaving harbor
2013 — in the strait
I found no photos from the 2011 and 2012 attempts, nor from the beginning of the 2013 attempt, in which any lines hang from the base of the boom.
But in photos from later in the 2013 attempt, all of a sudden there’s a lot going on down there. To grab those images, photographer Andy Newman rented a helicopter to get out into the strait. You can see some of Nyad’s surprised crew members looking up at the photographer (in the complete images: aerial view 1 / aerial view 2 / close to boat / close to boat, slightly wider angle).