The issue here was, how did the float free automatically hydrostatically activated Kannad F (with a Hammar type HRU, which was retrieved by Rockwater)
Kannad F is not automatic activation, it is just a float free model.
Here is a list of all Kannad Marine models oldest to newest before model names changed to 'Safelink' and 'Sportpro' to avoid confusion with Aviation models.
Kannad 406 Non Float-Free
Kannad 406 F Float-Free
Kannad 406 S Non Float-Free
Kannad 406 FH or Kannad 406 PH Float-Free
Kannad 406 S or Kannad 406 SW or Rescuer 406 S Non Float-free
Kannad 406 FW or Kannad 406 PW Float-Free
Kannad 406 ATP Automatic
Kannad 406 ATP-M Automatic
Kannad 406 XS Non Float-Free EPIRB/Manual
Kannad 406 AP or Kannad 406 AF or Kannad 406 AF-H Automatic
Kannad 406 Survival Manual Non Float-free
Kannad 406 AP or Kannad 406 AF or Kannad 406 AF-H or Kannad 406 AP-H Automatic
Kannad 406 ATP TAC Automatic ELT/Portable
Kannad 406 AF-H Automatic
Kannad 406 XS-2, Kannad 406 XS-2 GPS Float-Free
Kannad 406 GPS PRO Float-Free
Kannad 406 SVW GPS, Kannad 406 SV GPS Non Float-Free
Kannad 406 PRO Float-Free
Kannad 406 SVW, Kannad 406 SV Non Float-Free
Kannad Auto GPS, Kannad Automatic Float-Free
Kannad Manual + GPS, Kannad Manual +, Kannad Manual GPS, Kannad Manual Float-Free
Kannad 406 AF-Compact, Kannad 406 AF-Compact(ER) Automatic
As you can see the F model is float free but not automatic.
First model listed as automatic is the Kannad 406 ATP