2017-10-30Pacific Hydrographic BranchLTJG Sarah L ChappelOfficer in ChargeThe purpose of this survey was to respond to a USCG request for assistance locating missing Buoy “3”. It was located north of Cape Henry at the entrance to Cape Henry Channel. A cruise ship struck the buoy and may have dragged it north until it sank or came free from the ship. The Bay Hydro II was tasked to survey the York Spit Channel from G"37" & R"38" gate down to R"20" and then down to north of Cape Henry to help assist in clearing the precautionary area . The survey limits and methods (i.e., sensors used) were determined by the OIC of the Bay Hydro II in consult with the NRB Chief and NOAA Navigation Manager. The data from this survey are not intended to meet NOAA charting specifications, and are not intended to be applied to the nautical chart with the exception of hazards to navigation (i.e., DToNs), and potential anti-DToNs subject to branch review.The field unit produced a survey outline, bathymetric grid, and associated SSS mosaics. These products are submitted with this report to the Pacific Hydrographic Branch.All survey systems and methods utilized during this survey were as described in S-E924-BH2-17_DAPR.Soundings were reduced to Mean Lower Low Water (MLLW) using observed tides from Stations 8632200 (Kiptopeke, Chesapeake Bay), 8637689 (Yorktown USCG Training Center, York R.), 8638610 (Sewells Point, Hampton Roads), and 8638863 (Chesapeake Bay Bridge Tunnel).There were no DTONs created for this survey.Per the Project Instructions, the field unit determined one ATON (Green "25"buoy) to be missing. The team confirmed with local authorities that the buoy was known to be absent from the charted station. The multibeam surfaces show major heave and roll artifacts, due to poor weather conditions. These artifacts are more egregious in the MBES data east of the Chesapeake Bay Bridge Tunnel. The hydrographer post-processed SBETs in an attempt to alleviate these artifacts, but was unsuccessful in doing so.This survey does not meet charting specifications and is not adequate to supersede prior data.S-E924-BH2-17D00240VirginiaSouthern Chesapeake BayYork Spit Channel10000Edgetech4200Side Scan SonarKongsbergEM2040Multibeam SonarNorth American Datum of 1983 (NAD83)Mean Lower Low WaterVDatumUTM Zone 18NNOAA R/V BAY HYDRO II2017-10-052017-10-05LTJG Sarah L. Chappel2017-10-30