Posted on March 24, 2025
SAVANNAH, Ga. The U.S. Army Corps of Engineers’ Savannah District, the Engineer Research and Development Center and the Field Research Facility, in partnership with the City of Tybee Island, Georgia, installed test instruments to measure vessel waves on the island’s North Beach March 21, 2025, so engineers can ultimately design a solution which helps keep beachgoers safe from potentially hazardous vessel-generated waves.
Since the completion of the Savannah Harbor Expansion Project channel deepening in 2022, larger Neo Panamax vessels are now able to use the navigation channel. With the large ships comes large waves, and Tybee city officials along with beachgoers have voiced concerns about the hazardous wakes some of those larger vessels are causing.
The uncertainty of cause and effect makes early detection (of the wave size) extremely difficult. Overall, the wake produced by ships along the mildly sloping beaches of Tybee Island’s North Beach have the potential to generate a strong surge that can be hazardous for unsuspecting beachgoers. Therefore, the goal of the 2025 study is to determine the relationship between vessel operation, environmental conditions, and wake height, especially since all ships don’t generate large wakes.
“It’s great to have Dr. Styles and Bain back to continue the wake study at Tybee’s North Beach,” said Kimberly Garvey, USACE Savannah District Planning Branch chief. “With even larger ships coming into the channel, we need to better understand why some ships create large waves and others don’t. This (2025) study should give us the additional long-term data we need to gain a more accurate understanding, which will aid us in creating a comprehensive database that will be used to develop and evaluate methodologies to reduce the dangerous surge.”
Since scientist and engineers don’t completely understand why some large ships create dangerous waves, and other large ships create waves that are barely noticeable, a study was conducted in 2021, which identified a major knowledge gap existed due to the absence of long-term data collected in the surf zone. The updated 2025 project aims to fill the gap and enable validation of computer models.
“We are very excited to return to Tybee Island to collect data that will be used in conjunction with computer models to simulate the local conditions near the beach,” said Richard Styles, USACE Engineer Research and Development Center research oceanographer and senior team member. “We plan to simulate different alternatives to help identify measures that we could use in the future to reduce the surge on Tybee Island’s North Beach.”
The test instruments are metal pyramid-shaped structures that hold several devices used for measuring water pressure and flow velocity. There is also a hydraulic lift in the dunes that holds several cameras that automatically take photos of the ship channel and the beach. The data collected from the instruments and camera, alongside publicly available information used to identify the passing vessels will help scientists and engineers determine how tall the waves are, the water’s speed as it rushes across the beach and what direction the wave is arriving from (for each individual ship).
“While the original study amassed important information on ship operations in the channel,” Styles explained. “We did not collect enough data on the beach to answer the question of what combination of vessel operations and environmental conditions lead to the larger boat wakes.”
With the additional data gathered during the 2025 study, engineers will develop computer models of the ship wake, waves, and tides for model validation. Using the models, engineers can then determine if a breakwater is a feasible solution for reduction of vessel-generated wave energy, without causing a disruption of the sediment transport patterns near North Beach.
The 2021 study was gathered from 1,386 cargo vessel passages and 202 tanker passages, and also evaluated what is referred to as bathymetric data, which includes measurements and mapping the depths and shapes of underwater terrain. Likewise, it calculated high-frequency wave and vessel wake measurements which studied the characteristics of waves using sensors that capture the frequency and the fullness of the waves. Additionally, it included the data from the publicly accessible broadcast vessel identification system which automatically transmits a vessels identity, location, and other information to shore stations.
The original 2021 study was accomplished through the Army Corps of Engineers’ Planning Assistance to States Program and was cost-shared 50/50 between the Corps of Engineers and the City of Tybee Island. Even though the 2025 study is fully funded through the USACE’s Monitoring Completed Navigation Projects Program, the research team will continue to work in close coordination with city officials.
The Port of Savannah is the third-busiest container gateway in the United States, the fourth-largest seaport in North America and the second largest on the East Coast. The Savannah River navigation channel passes less than .6 miles north of Tybee Island.
For more details, please visit https://storymaps.arcgis.com/stories/b16f50278e234df68e56511fe08454c5.
To see a short YouTube Reel, visit https://youtube.com/shorts/xEsU6wu–xA?feature=shared
