I've always questioned the constitutionality of the without-probable-cause 'safety inspection' or 'catch inspection' stop. I expect that a canine search associated with one of those would send up a red flag on unreasonable searches.
I've always felt a handler , can get a dog to react to a signal,
Be it a word command or physical gesture.
Thus giving probable cause to rip your boat apart.
I've seen this happen to a friend of mines car after a seatbelt stop.
Cop had the dog jump on his car( constituting a hit)
Ripped his car apart
And left him putting the car back in place.
I don't trust them.