When judgment is rendered in favor of the plaintiff against a boat or vessel, and prior thereto it has been discharged from custody by the giving of bond or otherwise, or when for any reason the judgment or any part thereof remains unpaid for 60 days, the master and owner, or either, may be summoned to show cause why they should not be personally bound by the judgment. Such summons shall be subscribed by the judgment creditor, an agent or attorney, and shall describe the judgment, specify the amount due thereon, and require the party summoned to show cause within 20 days after the service thereof, and may be served in the same manner as a summons in a civil action. It shall be accompanied by an affidavit of the person subscribing it, to the effect that the judgment has not been paid or satisfied, except as specified in the summons, to the affiant’s knowledge, information, or belief.