The boat trailer in Ontario needs to be registered. It can be registered as either a home built or the registration can be transferred if there is a VIN on the trailer. The boat has to be registered with Transport Canada the boat registration is free. Takes two or three weeks and is done through the mail. Boat insurance is not mandatory at least the OPP has never asked for it when doing safety checks however if you do not have an valid operators card you will be fined.