Every day at 6 p.m., 85-year-old Judith walks the short distance to her younger sister Hanni’s house. They read poetry to each other and share a glass of vermouth as the sun sets.

They were great swimmers in Vienna once upon a time, when they belonged to the all-Jewish Hakoah sports club. In fact, Judith led the Austrian national team that was headed to the 1936 Olympics, but she refused to go to Munich, to protest the Nazis.

She was punished in various ways by the Austrian authorities, not least by having her numerous records excised from the books.

Judith’s bravery was approached by the gutsy Ana Marie, who took an enormous risk by joining the humongous crowd in Vienna’s Hildenplatz for Hitler’s speech on April 2, 1938.

These remarkable anecdotes are recounted in Yaron Zilberman’s heartwarming “Watermarks.” The documentary, which screened at the Contra Costa Jewish Film Festival in March, opens Friday, May 13, in the Bay Area.

“Watermarks” treks from Tel Aviv to Vienna to Los Angeles to introduce us to seven surviving members of the Hakoah swimming team of the 1930s. Hakoah represents one of the earliest examples of Jewish jocks dominating their non-Jewish competition and putting certain stereotypes to rest.

Although they are encouraged by the filmmaker to recall and reminisce about their formative years, it’s obvious that these vibrant, vital women don’t live in the past. Their lack of nostalgia for their youth and their satisfaction with the way their lives turned out gives “Watermarks” an air of gentle satisfaction.

At the same time, the film is inescapably a commentary on mid-century European anti-Semitism. But since the head of Hakoah was so diligent about spiriting the girls and their families safely out of Europe — and maintaining communication with them — this is by and large a happy story of long, healthy lives.

Those who appreciate irony will enjoy the saga of Elisheva, a non-observant Jew who journeyed to Palestine in 1935 to compete in the second Maccabiah Games. She was amazed at the warm welcome she received from her host family and the respect the parents showed the children.

When she got home, her Old World parents made fun of her effusiveness. “So, when are you going to Palestine?” they mocked. But Elisheva laughed last, as it turned out.

When the family was forced to flee Austria three years later, it was Elisheva’s connection with Hakoah that secured passage for the entire family on an illegal ship bound for Palestine.

Although it is sufficient to meet these women and bask in their spirit, the director has a hidden agenda: He wants to choreograph a reunion in Vienna and a group swim in the former Hakoah pool.

This leads to the octogenarians encountering a few people whose cluelessness underscores that, for a certain generation of European Jew, you can’t go home again.

“Watermarks” is not a transformational experience, but it is a gratifying and even inspiring one. In that regard it is superior to “The Ritchie Boys,” the recent doc that focused on the wartime exploits of a group of American intelligence officers a few years younger than the Hakoah women.

“Watermarks” opens Friday, May 13, at the Balboa Theatre in San Francisco and the Smith Rafael Film Center in San Rafael.