For nearly a year, from October 2017 to May 2018 anyone visiting the Edgartown library also had a chance to see art in the making.

Margot Datz had taken up residence in the children’s room, adding her touch to the room by painting a large marine mural. The finished product is a 65-foot-wide, floor-to-ceiling mural of marine life around the world. It is both whimsical and instructive, a specialty of Ms. Datz’s work around the Island.

On Friday, Oct. 12 from 5:30 to 7:30 p.m. there will be a party to officially celebrate the mural and Ms. Datz, and to recognize the donors who helped make the work a reality.

Ms. Datz said she estimated doing some 120 hours of research before even beginning the project.

“I became one of those ocean computer nerds, where at night I’d be having a cup of tea and reading about all kinds of crazy octopi,” she said in an interview earlier this summer.

The mural is divided into the sections depicting four of world’s seas: the Caribbean, Pacific, Indo-Pacific and Indian oceans.

“To the best of my ability, I really tried to represent the sea life of each of those oceans in a compatible way,” Ms. Datz said.

See for yourself during library hours or better yet thank the artist on Oct. 12. The Edgartown Public Library is located 26 West Tisbury Road in Edgartown.