Running lights location

Can't tell from your pic, but I would think that boat also has nav lights at the top of the mast (probably integrated into the mast) for when out in open water. These I expect to be used in more close quarters situations like at the start where they'll be jockeying for position and to cut off the wind from each other as it's real important to know where the stern is

Fishing vessels will seldom turn on their proximity alarms because they're on deck working and wouldn't hear it. Seldom will everyone on a fishing boat be sleeping. Sounds like Boris needs a louder alarm.

Just looked at the designs for these boat and yes they appear to have nav lights at the tops of the masts also.
http://chevaliertaglang.blogspot.com/2020/11/vendee-globe-challenge-2020-2021-yacht.html