MARBLEHEAD – Marblehead’s next director of public health will be Cape Codder Andrew Petty, who has served as Wellfleet’s assistant health agent and conservation agent since 2005.The Board of Health unanimously chose Petty Monday evening subject to negotiation of a contract after the board interviewed three finalists, including Marblehead Health Inspector Roberta Cody and Everett Director of Public Health Roberto Santamaria.Petty will take the place of Director of Public Health Wayne Attridge, who is scheduled to retire Jan. 4.The finalists were referred to the board last week by the Health Director Search Committee, which interviewed seven semi-finalists out of a field of 23 applicants.Petty, the last to be interviewed, was held at the meeting until the board concluded its brief deliberations. Called back to the meeting room, he accepted the post.In addition to Petty’s three years experience as a Board of Health member in Brewster, board members Helaine Hazlett, Michelle Gottlieb and Todd Belf-Becker were impressed that he had experience juggling work in two different areas in a small coastal community.Attridge, who attended the meeting and recused himself during Cody’s interview, offered positive comments on all three candidates. He called Cody “a good inspector with good ideas” but said she and Santamaria, who impressed Hazlett as “genuine” but only served eight months as director, needed more experience.The search committee included Chairman Carl Goodman, Polly Whitmore, Dr. David Becker, Don Morgan and Jane Bright. Board of Health Chairman Helaine Hazlett also served on the committee and Director of Public Health Wayne Attridge acted as an advisor. Goodman, Becker, Public Health Nurse Rochelle Bartlett and Selectmen Chairman Jackie Belf-Becker were in the audience for the interviews.The posting asked for applicants with an associate’s degree in the health field and eight-12 years experience. Cody has 11 years experience in the health field and an associate’s degree and Santamaria has a master’s degree in public health. Petty has a bachelor’s degree in environmental science.