MSB? Are you referring to the Marine Rescue guys?
There are crews at Cottage Point and Broken Bay who operate rescue boats in the area.
Here's what they look like:
marinerescuensw.com.au/I volunteer with they guys at Broken Bay but you could also have encountered the Cottage Point crew. Both patrol this area.
If this is who you are referring to, let me know and I'll put you in contact with the right folks.
Glad you made it back safely. Great kite spot there but not without it's challenges.
Rob