A favorite moment at family birthday parties is retelling the details of the child’s birth. In my own family, this season is blessed with birthdays. So in an unusual segue, I recently went from a grandson’s birthday celebration, where my own role as the nervous driver along Jerusalem’s winding roads to Ein Kerem with a daughter near-delivery in the passenger’s seat was featured, to the annual meeting of the Organization for the Commemoration of the Heritage of the Cyprus Detainee Camps, where this year’s theme was around the children born at sea. The organization devotes a study day each year to delve into the history of the so-called illegal immigration, or Aliyah Bet. These were the battered and bereaved Holocaust survivors literally seeking a safe harbor in the Land of Israel, in spite of the British authorities. They’re called ma’apilim, from a biblical Hebrew word meaning to “go up.”

Among the hundreds present at the Ben-Zvi Institute were children – now in their 70s – who were born on the rickety ships, and heroic sailing midwives Shula Gotlieb and Rachel Gilbert Katz. They told astounding stories of improvising amid the rolling waves and pursuing British warships. Gotleib described how she used the captain’s scissors to cut strands of her own long hair to tie an umbilical cord. Katz sewed sheets and diapers from the captain’s dress shirts.

The most famous of the ma’apalim ships was, of course, Exodus 1947, subject of Leon Uris’s inspirational novel and the movie starring Paul Newman. It sailed in July 1947. A less well-known ship that left eight months earlier from Yugoslavia was called Knesset Israel. This refitted Greek cargo ship was first named “The Hebrew Rebel Organization,” but the name was changed so as not to inflame the British more than necessary. The boat was readied with the help of sympathetic Yugoslavians. Reportedly, future president Josip Bros Tito even came to visit.

Jerusalemite Yosef Hamburger, better known as Yossi Harel (the character played by Newman as Ari Ben Canaan), was the commander.

Among the would-be passengers were Abraham and Esther Marmorstein.

Abraham survived a draconian labor camp; Esther was a slave laborer in Auschwitz. They both returned to their hometown of Kisvada, Hungary. Fellow young survivors from the Bnei Akiva youth group held the poles of the huppah. Their families were decimated. He was 24. She was 19.

Like so many survivors, instead of declining to bring children into a world of horrors, they wanted a baby. Impoverished and homeless, they were nonetheless delighted that despite the deprivations of Auschwitz, Esther became pregnant.

They crossed the border from Hungary to Yugoslavia, gathering with other refugees in Zagreb in a half-built university structure they entered with a ladder.

Finally, on November 5, 1946, Knesset Israel sailed toward pre-state Israel together with a smaller ship named for Abba Berdichev, the volunteer paratrooper who landed behind enemy lines and was murdered by the Nazis. Knesset Israel was carrying 3,445 passengers, Abba Berdichev 400.

Esther was in her ninth month, but was assured that the six-day voyage would take her to the shores of her homeland in time for the birth.

Three days into the journey, Esther began feeling labor pains.

At the same time, an intense winter storm moved onto the Adriatic Sea. The engine on the Berdichev died; the ship was drifting toward deadly mines. It landed on a rock. Now there were 3,845 survivors on board Knesset Israel.

Esther’s labor became more intense.

The doctor in charge of the ship clinic turned out to be a dentist.

An announcement was made by megaphone: “A: We need a carpenter to convert an officer’s cabin to a delivery room. B: We need an obstetrician or midwife for a woman in labor.” In the words of the late Abraham Marmorstein, “We were relieved when a very short but noble-spirited young woman named Ella Shichman came forward. Although she was seasick from the storm, she was ready to deliver our baby.”

An officer’s cabin was designated as the labor and delivery room. And there, the seasick nurse Shichman, a survivor from Chernowitz, delivered baby boy Marmorstein amid the wind, waves and pursuing British warships.

Eight days later, still at sea, the survivors celebrated the historic brit milah of the illegal immigrant – passenger 3,846 – born at sea. Abraham and Esther named him Mordechai for his maternal grandfather murdered in Auschwitz, but Knesset Israel’s radio officer – future pilot and MK Yoash Tsiddon – insisted they add “Sa’ar,” the Hebrew word for storm.

Until today, the distinguished author and professor of Zionist history bears the name Mordechai Saar Marmorstein on his identity card and passport.

Reaching the Dodecanese islands 12 days later, Knesset Israel was forced to seek shelter in a harbor of the rocky Greek island Syrina.

A British warship caught up with them and ordered them to go to Cyprus. They refused, so the British dispatched three destroyers to surround the survivors. When the soldiers began transferring passengers, the survivors fought back with tin cans and poles and scrawny arms tattooed with numbers. Two survivors were killed. Only when tear gas penetrated the baby room did commander Harel order the survivors to desist.

Not just baby Mordechai Saar was in the nursery. Thirteen children were born on the 23-day journey of Knesset Israel. Twelve survived. One was buried at sea.

The British sent the mothers and newborns to the detention camp in Atlit. The fathers were among those banished to Cyprus.

Fifty-two thousand Jews passed through the Cyprus camps with their crowded tents and tin-roofed barracks, limited water and rampant disease. Despite their pasts and the terrible conditions, the incarcerated survivors wanted to build families. Two thousand two hundred children were born. Midwives like Raquela Levy, the protagonist of Ruth Gruber’s book Raquela, were dispatched from Jerusalem to deliver them.

Ten months after they were separated, Abraham and Esther were reunited. They moved to Petah Tikva. Whenever they needed medical care for Mordechai Saar, they went to the Petah Tikva Kupat Holim clinic, where a familiar nurse named Ella Shichman was on duty.

Mordechai Saar and his wife, Mina, whose parents met and fell in love aboard the Exodus, have four children and 12 grandchildren. Today, they’re retired and like to travel. But when Mordechai’s Israeli passport is examined leaving Israel, a Sabra security officer will often defer to a superior about the unusual address under Place of Birth. It says “Knesset Israel ship.” Born on the high seas. If there’s time at the airport, he tells the intrigued young officer his birth story.