Engineers are not generally known for their superstition. But naval engineers do attach a certain mystique to the water inside “tow tanks,” the massive test basins where, for centuries, engineers have tested new ship designs for seaworthiness. Legend holds that the water itself soaks up a bit of new knowledge with each new test.

That’s why, on Feb. 24, 2026, Senator Gary Peters’s Office joined U-M faculty, students and staff in a traditional “mixing of the water”—a ceremonial pouring of water (and, perhaps, knowledge) from from 41 tow tanks in 19 countries into U-M’s newly-reopened Richard B. Couch Model Basin. These days, the water is mostly mailed in ahead of time, though visitors from Germany’s Hamburg Ship Model Basin, Sweden’s Kongsberg Hydrodynamic Research Center joined the festivities.

The event capped off months of renovations at the 750,000-gallon, 360-foot-long facility, which is the crown jewel of the Aaron Friedman Marine Hydrodynamics Laboratory. The basin was the first of its kind to be installed at an American university and is still the largest. Over its 120-year history, it has helped launch some of the most significant innovations in naval architecture, including the fuel-saving “bulbous bow” technology that’s used on nearly all of the large cargo ships that transport 90% of the world’s goods.

There’s no such thing as an average day at the facility. It’s referred to as the “tow tank” because engineers often use a motorized platform to drive model ships down the length of the tank, which helps test a vessel’s seaworthiness. On other days, a prototype wave energy converter might rock to the steady rhythm of waves, not to mention the numerous tests performed for external clients across the shipping, defense and marine energy industries.

“That we have so many participants at today’s ceremony is testimony to the fact that physical tanks, and the people that run them, are still critical in society and engineering although we share more and more of our workload with computer simulations,” said Kevin Maki, the director of U-M’s Aaron Friedman Marine Hydrodynamics Laboratory and a professor of naval architecture and marine engineering. “There’s a fellowship among the tanks that we want to celebrate.”

The lab is re-opening with a new wave-making system, which uses 24 independently moving paddles to make waves up to nearly two feet high that can hit a model ship from several directions. It’s a major upgrade to the previous system, which could only generate head-on waves of uniform height that could only swell to half the size. The new technology will enable engineers to more accurately evaluate the performance of their prototypes in stormy seas.

The wave makers are just the latest in a series of improvements over the past two years. ​​In 2024, for example, the tank’s carriage received a new control system and motors that enable finer speed controls and a wider variety of maneuvers that more closely resemble the movements of real ships. The new tools will help Michigan Engineers continue the tradition of scientific progress honored during the facility’s re-opening ceremony.

Some of the water mixed into the U-M tank dates back to the first-ever towing tank, built by William Froude in Torquay, England, in 1872. With the tank, Froude developed equations that he used to scale the amount of resistance felt by a model ship to a full-size vessel and describe the forces created by early propellers. Froude’s equations are still used by naval architects to predict a vessel’s performance using a scale model.

Froude’s son, Robert, followed his father’s example by building the world’s third tow tank in Haslar, England, in 1886, seven years after his father passed away. Robert Froude added water from the first tank into the new tank to commemorate his father, and the field has carried on the tradition ever since. Although the original Haslar Tank has since closed, QinetiQ (pronounced “kinetic”), the defense companythat manages the tanks at the Haslar lab, keeps water from the original tank for opening ceremonies.

“It’s a nice, tangible link back to William Froude and his son,” said Chris Richardsen, a principal consultant of engineering and operations at QinetiQ and the company’s unofficial historian. “Maybe a bit of that magic went into the new facility.”

For some, the “magic” is in Froude’s formulas, which have also enabled the breakthroughs of other world-class facilities that sent water to U-M. For others, the magic is felt in the experience working on the tow tank.

“When people step onto the carriage for the first time, you can really feel their energy and excitement as they start to see the spray of water and feel the carriage move,” said Jim Smith, a research project engineer at the Aaron Friedman Marine Hydrodynamics Laboratory. “It’s a really rich piece of U-M history.”