Sailboat was built to travel the world. Instead, it has commanded the St. Croix River since 1951.

There’s no other boat quite like the Dar-Ja sailing the St. Croix River, gliding along the shoreline, its twin masts outfitted with white triangles of sail billowing across the bow like a New England schooner.

The sailboat that Jack Lown built in a back yard in Iowa was supposed to take him on an around-the-world voyage with three friends. That was before World War II broke out, and two of Lown’s buddies died fighting overseas. What happened next became Lown’s true sailing adventure, one that never left the Midwest, touched salt water or charted a course across an ocean.

Sailing into its eighth decade, the wooden sailboat first launched in 1951 has become an iconic St. Croix River vessel, still piloted by the same family that grew up on it and still drawing attention from sailors and non-boaters alike.

“I remember Mom and Dad dancing on the deck,” said Mary Ann Bergquist, one of the daughters of Jack and Darlene Lown. Her parents floated up the Mississippi River from Waterloo, Iowa, a few years after they married in 1948, back when the boat named for them had a motor but no masts or sails.

The Lowns had seven children, danced twice a week at Twin Cities-area ballrooms and spent the sailing season aboard Dar-Ja when Jack took a long break each summer from teaching high school industrial arts.

The boat that was to conquer the globe instead found a home in Stillwater for several years and then, after Lown got tired of waiting for the Stillwater Lift Bridge to open, Hudson, Wis., in 1954. Over more than 70 years, the boat has been launched countless times to sail north to Stillwater or as far south as Lake Pepin.

Jack died in 1987 and Darlene in 2012. Today their surviving children sail Dar-Ja, especially their son John Lown, who said he takes it out three to four times a week. The boat has sailed so many times, and with so many people, that John said it’s not uncommon for him to be at a store somewhere and have someone approach him with their Dar-Ja story.

John said he was sailing one day when a Zodiac zipped up behind him. It was Stan Hubbard, the owner of KSTP, delivering pictures he had of Dar-Ja under sail.

A young Jack Lown first imagined sailing around the world after reading “Around the World Single-Handed” by Harry Pidgeon. An uncle and his father had built dozens of boats, and by the time Jack Lown was 15, he had built his own motorized riverboat. It wasn’t until his early 20s as he studied to become a teacher that he began work on the boat that would become the Dar-Ja.

He first had his plans checked by a naval architect in Chicago, then built a 4-foot model. The full-size version, of oak and spruce and fir, is 12 feet across and weighs some 28,000 pounds when fully loaded with fuel and water. Its middle deck section above the cabin makes a good dance floor.

After the boat was built, Lown got a permit to haul it the 90 miles to Dubuque, Iowa, and the Mississippi River, first launching it in 1951.

Jack Lown never officially chartered the boat as a business, but friends soon learned that he would go out most weekends with a full crew. Lown told a newspaper in the 1970s that he was taking some 2,000 people a year out on the St. Croix River. His family took several trips each summer to Lake Pepin; the boat can sleep 12 people and has a full kitchen and bathroom.

Son John said growing up with the Dar-Ja meant sailboat construction was ongoing. The wooden ship has seen its hull replaced and its main mast and engine. A second mast built in 1978 was partly completed at the former Frank B. Kellogg High School in Little Canada, where Jack was teaching industrial arts.

It was finished at the family home in northeast Minneapolis, then delivered by car and specialized trailer to the St. Croix River. To install the new mast, Jack’s son Curtis Lown stood on the Interstate 94 bridge with a block and tackle to raise the mast up from the deck of the Dar-Ja, which was floating below.

“Can you imagine that now?” Curtis said.

The boat has had close calls — Curtis remembers a time when he took it out for his birthday and the Dar-Ja was hit with a massive straight-line wind. The boat leaned over, the cockpit filled with water, and someone called the sheriff for help.

“It was just a freak deal,” said Curtis.

On a night in 1958, a motorboat driver slammed into the ship’s prow at full speed, killing the driver, a 58-year-old man from St. Paul.

Sailing on the river means the Lowns know the bridges over the St. Croix and whether the Dar-Ja and its 56-foot-tall mast can pass underneath.

Even sailing under the Interstate 94 bridge can feel like sailboat limbo with river levels at moderate flood stage this past week.

The I-94 bridge is fixed, but others have a bridge operator to lift or swing open a section.

It was at the Prescott, Wis., bridge that Mary Ann used to jump off the boat as a child and run up to the bridge operator’s house. “I knew where the bridge man lived,” she said, “and I would run up to his house and say, ‘You have to open the bridge!’”