heres some info i found
Vessel Boat Registration and Information
The following vessels do not have to be registered in California:
Vessels propelled solely by oars or paddles.
Non motorized sailboats that are eight feet or less in length.
Non motorized surfboards propelled by a sail and with a mast that the operator must hold upright.
A ship’s lifeboat (a dinghy is not a lifeboat).
so it appears you dont need to register it if you row it and dont use the motor. with any motor you have to register it in California
here in WA you dont need to register a tender as long as all it does is between shore facilities and your main vessel.