Upon the completion of the hearing, the board of supervisors shall have a finding of facts entered upon the minutes if it appears that:
(a) The petition and notice of hearing have been duly published.
(b) The petition is signed by a sufficient number of persons who possess the required qualifications.
(c) A harbor exists within the proposed district.
(d) The harbor can be improved and developed as generally described in the petition.
(Enacted by Stats. 1937, Ch. 368.)