ORS § 783.330
The person so injured may at the time of filing the complaint, or at any time subsequent thereto, cause an attachment to issue against the vessel. The clerk of the circuit court shall issue a writ of attachment directing the sheriff of the county to levy upon, seize and take the vessel; but such attachment shall only issue upon the filing by the plaintiff of a written motion for such attachment, together with an undertaking in a sum equal in amount to the sum demanded in the complaint. The undertaking shall be executed by one or more sureties, and shall be so conditioned that the signers thereof shall be liable in the sum named therein to the owners of the vessel if the attachment is wrongful or without sufficient cause. The sureties shall in the aggregate justify in double the amount of the undertaking.
ORS 783.330