During the Operation FORAGER: Expanding Documentation and Research of WWII Maritime Heritage project (2017), archaeologists used photogrammetry, or the science of taking measurements from photographs, as a way to record underwater sites on the heritage trail. This method offers rapid documentation of a site and can supplement traditional recording methods in creating site plans and measuring data. The photogrammetric surveys resulted in 3D models and site plans. Photogrammetry expert Dr. Kotaro Yamafune oversaw the production and post-processing of hundreds of photographs from each site to create the models. Models were created to scale and color corrected using Agisoft PhotoScan software. The models created on this project will be compared to previous photographs and site plans to see how the sites have changed over time and how they have been impacted by natural and cultural factors. The resulting models also serve as public outreach tools that can be 3D printed or viewed on touch screens and computers.
Another aspect of Operation Forager was the survey of Tinian’s WWII invasion beaches Unai Babui (White Beach) and Unai Chulu (White Beach 2). Anomalies, or areas of interest, were dived on and resulted in the crew finding an enormous WWII Danforth anchor and a previously unknown, fairly intact LVT in approximately 45 ft. of water. Swim line searches were also conducted and portions of a second LVT were located in approximately 20 ft. of water. Another large stockless US Navy anchor was found in 20 ft. of water and a tire belonging to a DUKW, a vehicle used for transporting troops and equipment on land and on water. Further research on these sites may reveal the specific vehicles because so few were lost and the details of their losses are known through documentation. Operation FORAGER was funded with the help of the NPS’s American Battlefield Protection Program (ABPP). The project follows previous ABPP grants supporting the identification, recording, and protection of heritage from the WWII battle for Saipan and Tinian in the Mariana Islands.
For more information on Operation FORAGER see the grant report.