A vessel is deemed rebuilt foreign when any considerable part of its hull or superstructure is built upon or substantially altered outside of the United States. In determining whether a vessel is rebuilt foreign, the following parameters apply:

(a) Regardless of its material of construction, a vessel is deemed rebuilt when a major component of the hull or superstructure not built in the United States is added to the vessel.

(b) For a vessel of which the hull and superstructure is constructed of steel or aluminum—

(1) A vessel is deemed rebuilt when work performed on its hull or superstructure constitutes more than 10 percent of the vessel's steelweight, prior to the work, also known as discounted lightship weight.

(2) A vessel may be considered rebuilt when work performed on its hull or superstructure constitutes more than 7.5 percent but not more than 10 percent of the vessel's steelweight prior to the work.

(3) A vessel is not considered rebuilt when work performed on its hull or superstructure constitutes 7.5 percent or less of the vessel's steelweight prior to the work.

(c) For a vessel of which the hull and superstructure is constructed of material other than steel or aluminum—

(1) A vessel is deemed rebuilt when work performed on its hull or superstructure constitutes a quantum of work determined, to the maximum extent practicable, to be comparable to more than 10 percent of the vessel's steelweight prior to the work, calculated as if the vessel were wholly constructed of steel or aluminum.

(2) A vessel may be considered rebuilt when work performed on its hull or superstructure constitutes a quantum of work determined, to the maximum extent practicable, to be comparable to more than 7.5 percent but not more than 10 percent of the vessel's steelweight prior to the work, calculated as if the vessel were wholly constructed of steel or aluminum.

(3) A vessel is not considered rebuilt when work performed on its hull or superstructure constitutes a quantum of work determined, to the maximum extent practicable, to be comparable to 7.5 percent or less of the vessel's steelweight prior to the work, calculated as if the vessel were wholly constructed of steel or aluminum.

(d) For a vessel of mixed construction, such as a vessel the hull of which is constructed of steel or aluminum and the superstructure of which is constructed of fibrous reinforced plastic, the steelweight of the work performed on the portion of the vessel constructed of a material other than steel or aluminum will be determined, to the maximum extent practicable, and aggregated with the work performed on the portion of the vessel constructed of steel or aluminum. The numerical parameters described in paragraph (b) of this section will then be applied to the aggregate of the work performed on the vessel compared to the vessel's steelweight prior to the work, calculated as if the vessel were wholly constructed of steel or aluminum, to determine whether the vessel has been rebuilt.

(e) The owner of a vessel currently entitled to coastwise or fisheries endorsements which is altered outside the United States and the work performed is determined to constitute or be comparable to more than 7.5 percent of the vessel's steelweight prior to the work, or which has a major component of the hull or superstructure not built in the United States added, must file the following information with the National Vessel Documentation Center within 30 days following the earlier of completion of the work or redelivery of the vessel to the owner or owner's representative:

(1) A written statement applying for a rebuilt determination, outlining in detail the work performed and naming the place(s) where the work was performed;

(2) Calculations showing the actual or comparable steelweight of the work performed on the vessel, the actual or comparable steelweight of the vessel, and comparing the actual or comparable steelweight of the work performed to the actual or comparable steelweight of the vessel;

(3) Accurate sketches or blueprints describing the work performed; and

(4) Any further submissions requested by the National Vessel Documentation Center.

(f) Regardless of the extent of actual work performed, the owner of a vessel currently entitled to coastwise or fisheries endorsements may, as an alternative to filing the items listed in paragraph (e) of this section, submit a written statement to the National Vessel Documentation Center declaring the vessel rebuilt outside the United States. The vessel will then be deemed to have been rebuilt outside the United States with loss of trading privileges.

(g) A vessel owner may apply for a preliminary rebuilt determination by submitting:

(1) A written statement applying for a preliminary rebuilt determination, outlining in detail the work planned and naming the place(s) where the work is to be performed;

(2) Calculations showing the actual or comparable steelweight of work to be performed on the vessel, the actual or comparable steelweight of the vessel, and comparing the actual or comparable steelweight of the planned work to the actual or comparable steelweight of the vessel;

(3) Accurate sketches or blueprints describing the planned work; and

(4) Any further submissions requested by the National Vessel Documentation Center.