The town election season this year will feature contested races for selectmen in Oak Bluffs and West Tisbury, as a full slate of candidates vie to fill the seats of two outgoing incumbents.

In West Tisbury, selectman Dianne Powers decided not to run again after serving a single term on the three-member board. When reached by phone this week Ms. Powers, also Dukes County register of deeds, offered a simple reason why she was calling it quits after one term. “I need to focus on my work at the registry of deeds,” she said.

The opening has drawn two challengers, one a familiar face and the other a relative newcomer.

Cynthia Mitchell, a former four-term selectman, is looking to return to the board after an eight-year absence, while Erik Hammarlund is running for the first time. Mrs. Mitchell lost her seat in 2002 after Glenn Hearn defeated her by 20 votes. She has since been elected to the board of assessors; she works as director of the Island Health Plan.

Mrs. Mitchell said this week that she misses being a selectman and feels there is much she can contribute.

“I love the town, and I know the job. I miss serving the town I care so much for,” she said.

Mr. Hammarlund is a past associate member of the planning board, and a current member of the board of trustees for the Vineyard Conservation Society. He also serves on the board of trustees for Island Children’s School. He said he decided to run because he wanted to give something back to the town.

“West Tisbury is such a great town. I am not coming in saying I am looking to change this or that. But I do think I listen to people and am a hard worker. I also will come in without agendas or preconceived notions,” he said.

The race for selectman is the only contest in West Tisbury this year; Richard Cohen is running unopposed for assessor to fill Mrs. Mitchell’s seat. There is an opening on the parks and recreation committee; although no candidates took out papers, a write-in candidate can win the seat.

There will also be a tight race for selectman in Oak Bluffs, as two-term incumbent Kerry Scott chose not to run again. There are four candidates: Gail Barmakian, Kris Chvatal, Kenneth Davey and Karen Achille.

Ms. Barmakian is a former member of the zoning board of appeals and current wastewater commissioner. She ran unsuccessfully for selectman last April, losing to Kathy Burton by less than 100 votes in a crowded race.

Ms. Achille is a member of the council on aging and a library trustee. Mr. Chvatal is a teacher at the Martha’s Vineyard Regional High School; he is also a current member and chairman of the zoning board of appeals. Mr. Davey works as an Oak Bluffs emergency medical technician.

In another contested race, Sharon Rzemien, George Warren and David Oliveira are vying for two seats as town constable.

All other races are uncontested.

The election in both towns is April 15; the annual town meeting is April 13.