Reviewing A Tragic Man Overboard

Bruce Thompson compiled the following data regarding the accident at the start of the 2018 Chicago Mackinac Race which cost Jon Santarelli his life.

Exhibit One

This is a screenshot taken from the race tracker of Imedi’s track on the afternoon of July 21. To orient those unfamiliar with the area, at the upper left hand corner is Belmont Harbor (3200 North).

Moving down the coast you can see Diversey Harbor, the entrance is near Diversey (2800 North) and the south end is at Fullerton (2400 North). Near the bottom you can see the Water Filtration Plant at Ohio (600 North) and below it is Navy Pier at Grand Ave (400 North).

The rhumb line is in red. Imedi’s track is in gray. It stops about as far north as Fullerton. Since every 800 street numbers equals one statute mile, and Imedi got to 2400 North which was about three miles north of the start.

The track also roughly agrees with the report that his body was recovered six miles east of Belmont Harbor. In effect, he was found about where he fell overboard, or maybe even a bit north of that point.

The conclusion is that he drowned relatively quickly after falling overboard and sank to the bottom. From that point onward, a surface search and rescue mission was going to prove unsuccessful because he was no longer on the surface.

Exhibit Two

This is the plot of Significant Wave Height taken at the Wilmette Weather Buoy, NDBC 45174. Note that the time shown are GMT so you need to subtract five hours to get CDT. The accident took place about 14:45 CDT (09:45 GMT). The wave heights were building and about 5-6 feet.

Exhibit Three

This is the plot of the Dominant Period of the waves at Wilmette. The dominant wave period at the time of the accident was 5 seconds.

Discussion
The beaches in Chicago were closed due to a high wave warning.

To get a better understanding of what it is like to be in 5 foot waves with a 5 second period, try running up and down six stairs in five seconds. Then repeat until exhaustion sets in.

Jon Santarelli was a tri-athlete, but triathlons are swum in flat water wearing a swimsuit, not swimming up the face of a wave wearing foul weather gear and boots.

Given that his inflatable life jacket failed to inflate, he had a matter of minutes to survive until exhaustion set in and he drowned. It was all over but the recovery mission in just a few minutes.

How things might have been different had he been tethered to the boat? That is the question sailors should be asking themselves.