(a) To protect archaeological resources, your EP, DOCD, or DPP that proposes activities involving disturbance of the seafloor must be accompanied by or contain one of the following:

(1) An archaeological report based on a high-resolution geophysical (HRG) survey of the APE defined, pursuant to 36 CFR 800.16(d) of the Advisory Council on Historic Preservation's regulations implementing section 106 of the NHPA, as the depth and breadth of the seabed that could potentially be impacted by proposed activities;

(2) A reference to an archaeological report based on an HRG survey of the APE that you previously submitted for your lease, provided that any previously submitted survey complies with the survey parameters identified in these regulations and the results of the survey are, in BOEM's judgment, valid. BOEM may consider a survey or the resulting report to be invalid if BOEM suspects that changes to the seafloor environment warrant acquiring additional data, considering, for example, the time elapsed since the prior survey or change in seafloor from a geological event such as a mudslide; or

(3) Evidence demonstrating to BOEM's satisfaction that a reasonable and good faith effort to identify archaeological resources within the APE has already been performed, provided that the past efforts are sufficient to identify possible marine archaeological resources at a degree of certainty reasonably similar to or better than an HRG survey.

(b) The archaeological report and evidence described in paragraph (a) of this section must have been or be prepared and signed by a qualified marine archaeologist. A qualified marine archaeologist must meet the Secretary of the Interior's “Standards and Guidelines for Historic Preservation Projects: Professional Qualifications Standards” as developed per the National Historic Preservation Act (54 U.S.C. 306131), and any subsequent updates to those standards and guidelines, and must have experience in conducting or overseeing HRG surveys and processing and interpreting the resulting data for archaeological potential.

(c) The geophysical survey resolution for the surveys described in paragraph (a) of this section must be sufficiently detailed to identify potential archaeological resources and must be performed using instrumentation and methodology that is state-of-the-art and that meets or exceeds scientific standards for conducting marine archaeological surveys. The surveys must, at a minimum, adhere to the following operational requirements and performance standards:

(1) A state-of-the-art navigation system with sub-meter accuracy able to continuously determine the surface position of the survey vessel and in-water position of towed and autonomous survey sensors. Position fixes must be digitally and continuously logged along the vessel track. Geodesy information must be clearly presented and consistent across all data types. Navigation systems meeting the criteria outlined in this section do not require prior approval by BOEM.

(2) For geophysical surveys conducted in water depths of 100 meters (328 feet) or less, the survey must employ a total field magnetometer, gradiometer, or other similar instrument having equal or superior measurement capability. The magnetometer, gradiometer, or its equivalent must be towed as close to the seafloor as possible and sufficiently far from the vessel to isolate the sensor from the magnetic field of the survey vessel and the other survey instruments. The magnetometer, gradiometer, or its equivalent must be towed at a sufficient altitude to detect ferrous metals or other magnetically susceptible materials of at least 1,000 pounds (453 kilograms) in mass with a minimum magnetic deflection of 5 gamma (γ; 5 nanotesla [nT]). An accurate method must be used to record the height of the magnetometer, gradiometer, or its equivalent in the water column. The altitude of the magnetometer, gradiometer, or its equivalent must be continuously recorded during data acquisition along the survey. The instrument's sensitivity must be 1 γ (1 nT) or less. Background noise level must not exceed a total of 3 γ peak to peak with data samples of at least 2 points per meter along the survey track. All collected data must be recorded on a digital medium that can be linked electronically to the positioning data. Survey line, time, position, altitude, and speed must be annotated on all output data. The data must be post-processed and contoured in a manner to best facilitate the interpretation of potential archaeological resources.

(3) For geophysical surveys conducted to locate potential areas of prior human occupation, a sub-bottom profiler system must be used to identify and map buried geomorphological features of archaeological potential that may exist within the horizontal and vertical APE, taking into account the geomorphology of the operational area and the parameters of the proposed project (including the maximum depth of disturbance from the proposed activities). The use of a sub-bottom profiler is required in water depths of 140 meters or less, unless BOEM specifies a different water depth based on its determination of the furthest extent of prior human occupation on the OCS. The sub-bottom profiler system must be capable of achieving a depth of penetration and resolution of vertical bed separation that is sufficient to allow for the identification and cross-track mapping of features of archaeological potential (e.g., shell middens, paleochannels, levees, inset terraces, paleolagoon systems, and other relict landforms). The sub-bottom profiler system employed must be capable of achieving a resolution of vertical bed separation of at least 0.3 meters (1 foot) in the uppermost 10 to 15 meters (33 to 50 feet) of sediments, depending on the substrate.

(4) In all water depths, a side-scan sonar or equivalent system must be used to provide continuous planimetric imagery of the seafloor to identify potential archaeological resources on and partly embedded in the seafloor. To provide sufficient resolution of seafloor features, BOEM requires the use of a system that operates at as high a frequency as practicable based on the factors of line spacing, instrument range, and water depth. The sonar system must detect small, discrete targets 0.5 meters (1.6 feet) in length at maximum range, along the track. The instrument range must provide at least 100 percent overlapping coverage (i.e., 200 percent seafloor coverage) between adjacent primary survey lines. Greater than 200 percent overlapping coverage may be necessary to guarantee nadir coverage and account for survey vessel drift between lines, which may be an important consideration when surveying in deep water. The side-scan sonar sensor must be towed above the seafloor at a height that is 10 to 20 percent of the range of the instrument. Data must be digitally recorded and visually displayed to monitor data quality and identify targets of interest during acquisition. The data must be post-processed to improve data quality by, for example, adjusting for slant range effects and variable speed along line.

(5) In all water depths, an echo sounder or equivalent system must be used to measure accurate water depths across the area. Where swath bathymetry data are acquired, it is recommended that backscatter values from the seabed returns are logged and processed for use in seabed characterization to support and complement the side scan sonar data. Single beam echo sounder data (or data from the equivalent system) must be used to verify the results of swath bathymetry data to check for gross error. The bathymetry systems must be set up to accurately record data across the range of water depths expected in the survey area. Care must be taken in selection of operating frequencies such that the individual systems do not interfere with each other. The bathymetry systems must be used in conjunction with an accurate motion sensor to compensate for vessel motion. Water column sound velocity must be determined as a minimum at the start and end of data acquisition, and at suitable intervals throughout the project, by use of a conductivity, salinity, and temperature depth probe or a direct reading sound velocity probe suitable for use in the maximum water depths expected within the survey area. Water depths must be corrected for vessel draft, tidal level, and referenced to the appropriate vertical datum (LAT, MSL, etc.). The final processed digital terrain model data cell size covering the entire survey area, without gaps, must reflect the frequency of the system being used, data density, and altitude above seabed of the transducer head.

(6) An archaeological survey conducted prior to the effective date of these regulations may be used in lieu of conducting a new survey, subject to BOEM approval, provided the lessee or operator can demonstrate that such survey was conducted in such a manner as to meet the objectives of this paragraph (c).

(d) The Regional Director may approve a departure from the provisions of paragraph (c) of this section on a case-by-case basis if the Regional Director deems the departure necessary because the applicable requirements, as applied to a specific circumstance:

(1) Are impractical or unduly burdensome;

(2) Are not necessary to achieve the intended objectives of the marine archaeology program;

(3) Fail to conserve the natural resources of the OCS;

(4) Fail to protect life (including human and wildlife), property, or the marine, coastal, or human environment; or

(5) Fail to protect sites, structures, or objects of historical or archaeological significance.

(e) Any departure approved under this section must:

(1) Be consistent with requirements of the OCS Lands Act;

(2) Protect the archaeological resources to the same degree as if there was no approved departure from the regulations;

(3) Satisfy section 106 of the National Historic Preservation Act and achieve results for identifying archaeological resources as if there was no approved departure from the regulations;

(4) Not impair the rights of third parties; and

(5) Be documented in writing.

(f) BOEM may reject any archaeological report if the survey was not prepared in accordance with the requirements of paragraph (c) in this section or any BOEM-approved departure to the survey requirements. BOEM may also reject any archaeological report if the results produced from the survey do not meet the data and resolution requirements specified under paragraph (c), regardless of whether the survey was otherwise conducted appropriately.

(g) If the archaeological report or evidence mentioned in paragraph (a) of this section suggests that an archaeological resource may be present, you must:

(1) Situate your operations so as not to adversely affect the area where the known or suspected archaeological resource may be located; or,

(2) Establish, to the satisfaction of the Regional Director, that an archaeological resource does not exist by conducting further archaeological investigation, under the supervision of a qualified marine archaeologist, using equipment and techniques the Regional Director considers appropriate. You must submit a report documenting the further investigation to the Regional Director for review;

(i) If the further investigation cannot establish to the satisfaction of the Regional Director that an archaeological resource is not likely to be present at the operational site, you must demonstrate to the satisfaction of the Regional Director that your operations will not adversely affect the suspected resource; or,

(ii) If, based on the additional archaeological investigation, the Regional Director determines that an archaeological resource is likely to be present in the operational site and may be adversely affected by operations, you must take whatever additional steps are specified by the Regional Director to protect the archaeological resource before you conduct any further operations at the operational site; or,

(3) If the Regional Director determines that an archaeological resource is likely to be present in the lease area, that it is likely to be adversely affected by your operations, and that there are no feasible means to avoid this adverse effect, the Regional Director may prohibit your operations in the APE.

(h) Any lessee or operator that has an existing lease in effect prior to October 3, 2024 may apply the regulations in effect prior to this date with respect to the provisions of this section for such lease for a period of time not to exceed September 3, 2025.