by Lt. Madeleine Adler, NOAA, Navigation Officer, NOAA Ship Ferdinand R. Hassler
NOAA Ship Ferdinand R. Hassler recently submitted a multibeam echo sounder survey of two sunken World War I era battleships to the Office of Coast Survey. Hassler, which was commissioned earlier this summer, surveyed the site of these two wrecks while transiting through the area during test and evaluation operations in 2011, and has been using the resulting dataset for calibration purposes since then. Although the wreck locations were well known, they had never been surveyed with modern techniques.
The ships are USS New Jersey and USS Virginia, which were intentionally sunk during aerial bombing experiments in 1923. U.S. Army Colonel Billy Mitchell, a pioneer of military aviation, urged the Navy to investigate the effectiveness of aerial bombing against surface vessels. As part of a series of tests, the Navy anchored the two obsolete “White Fleet” battleships off Cape Hatteras in September 1923 to serve as targets. Bombers under Mitchell’s direction sank both ships in short order. The success of these tests had a significant influence on subsequent development of U.S. air power and air defense for naval vessels.
Hydrographic survey systems require thorough calibration and testing before data can be accepted for application to NOAA nautical charts. New Jersey and Virginia rest in water approximately 100 meters deep, making them excellent test targets for Hassler’s Reson 7111 mid-water depth multibeam echo sounder system. Hassler surveyed the wrecks during a trial voyage from Pascagoula, Miss., to Norfolk, Va., in 2011, and the crew used this dataset and others to calibrate the echo sounder. Hassler’s survey systems are now fully operational, and the survey is ready for submission.
Coast Survey will use the survey of USS New Jersey and USS Virginia to update nautical charts of the area, and NOAA’s Office of National Marine Sanctuaries personnel will study it to further their understanding of marine archeology and the seafloor in the vicinity of Monitor National Marine Sanctuary.
NOAA Ship Ferdinand R. Hassler was commissioned on 8 June 2012, and continues to survey mid-Atlantic coastal waters for charting, fisheries and ocean exploration.