Vessel Profile: North River Boats’ Sounder

A workboat by Oregon-based North River Boats ushers in a new Sounder family of vessels.

The 26-foot survey vessel Sounder, built by Oregon-based North River Boats. Photo: NRB.

North River Boats has built the new 26-foot survey vessel Sounder for the U.S. Army Corps of Engineers (USACE) of Los Angeles.

The Sounder is the flagship for a larger series of customizable workboats at North River Boats, based in Roseburg, Ore., that can be scaled from 23 feet to 60 feet in length with beams ranging from 8 feet, 6 inches to 16 feet.

For the company, the combination of the boat hull, trailer-able size, topline outfitting and electronic configuration puts the Sounder in play as the most versatile survey vessel of its size on the market. The vessel was on display at the 2022 International Workboat Show in New Orleans.

Inception and Construction

According to North River Boats’ Jesse Faunce, the project began as a referral from a hydrographic survey company called Seafloor Systems in late 2020.

“Seafloor had an existing relationship with the USACE L.A. hydrographic survey team supplying them equipment in the past,” Faunce explained. “USACE L.A.’s current boat had reached the end-of-life cycle and they were in need of a new boat to maintain their routine surveys on the 18 harbors they cover in their district from Morrow Bay to San Diego Harbor.”

A Corps of Engineers L.A. hydrographic survey team led by Tyler Overmire was tasked to replace their outdated survey boat with a new, top-of-the-line vessel to provide highly accurate surveys safely and efficiently.

The boat had to be large and stable enough to provide ample room for the typical two-person crew along with the necessary survey equipment and software. After awarding North River Boats the project, USACE L.A. and Seafloor collaborated with the firm on a series of design proposals.

“Once we received final approval on the drawings and systems from USACE L.A. we began the process of fabrication, paint, outfitting and Seafloor survey equipment integration and final quality control and sea trials,” Faunce said. The overall production process on the shop floor took about eight months from start of fabrication to sea trials.

Design Features

A notable design feature that sets the new boat apart from industry norms is the replacement of the moon pool for survey equipment deployment with a side-mounted sonar arm. Seafloor Systems provided a multibeam echo sounder and LIDAR equipment to be used for hydrographic survey, dredging, inspection, infrastructure and channel maintenance surveys.

“Through the utilization of a pair (of) Universal Sonar Mount Side deployment arms mounted on the aft cockpit gunwales, we were able to maintain a large open unobstructed deck space,” Faunce explained.

“With the dual USM arms, Seafloor was able to mount two Teledyne Reson T50 Multibeam sonar heads, one off each side of the boat,” he continued. “With multi-beam sonar heads being deployed off each side of the boat, in most cases it doubles the width of survey path thus cutting their survey time in half.”

In addition to the dual multi-beam sonar heads, Seafloor installed a Merlin LIDAR laser scanner allowing not only a full bottom mapping of the harbors but also a topside surface scan of the surrounding surface borders of the harbors.

With the boat and survey equipment combined, the reported effective accuracy range of the mapping produced is within 1 cm to 1.5 cm of accuracy.

Another feature of the boat is a larger battery capacity that extends survey operations without having to run a back-up generator. The Sounder’s deep vee hull is purported to be a safer boat for surveying both offshore and near-shore environments. Its slim 8-foot, 6-inch beam provides the versatility of being trailer-able without requiring special permits.

“The best innovation of this project is really the entire package as a whole,” Faunce said. “Utilizing our Sounder hull for the footprint to build this boat set it up for great stability and versatility, which is not common to have both on most survey vessels.”

Looking Ahead

The boat passed sea trials and equipment testing in November before it was exhibited at the work boat show in New Orleans. Post-show, the boat was delivered back to North River Boats for a final cleaning and then shipment to the USACE L.A. district office in December.

Faunce and North River Boats Sales Director Mike Blocher were scheduled to travel to Los Angeles in January for a week of vessel reactivation and on-water training with the USACE L.A. team.

“Seeing Tyler and his team so excited about the final outcome of this project definitely feels great,” Faunce said, pointing to the satisfaction of seeing “this state-of-the-art solution” put into service, “knowing how much safer and more efficient their work will be.”  


Norris Comer is a Seattle-based writer and author. His debut memoir, Salmon in the Seine: Alaskan Memories of Life, Death, & Everything In-Between is now available wherever books are sold. You can find him on Substack, Instagram and at He can be reached via email at