Oregon Revised Statutes Shipping and Navigation § 778.235

(1) If a commissioner appointed pursuant to ORS 778.215 refuses to serve, ceases to have the qualifications required by ORS 778.210 (1) or fails to attend for the period of 60 successive days any of the regular or special meetings of the board regularly and duly called and held, the commissioner's place on the board is vacant.

(2) The board may grant a leave of absence not exceeding three months to a commissioner unable to attend meetings of the board by reason of illness or continued absence from the City of Portland.