Hey Baddawg,

I have the same issue, and reluctantly unscrew and remove my riggers after each use so they are not sitting mounted on my boat in the driveway for a thief to take.

I guess the best way to set them up to remove them quickly would be to modify your mount to a Gimbal mount that just slides in and out, kind of like a quick release.
Or you could use a clamp mount.

I looked at trying to figure out a way to lock my riggers onto my boat but there really isnt any way I could think of except useing something like a bike chain lock.