Wisconsin Shipwreck Coast National Marine Sanctuary consists of an area of approximately 726 square nautical miles (962 square miles) of Lake Michigan waters within the State of Wisconsin and the submerged lands thereunder, over, around, and under the submerged underwater cultural resources in Lake Michigan. The precise boundary coordinates are listed in Appendix A to this subpart. The eastern boundary of the sanctuary begins approximately 9.3 miles east of the Wisconsin shoreline (as defined by the low water datum) in Lake Michigan at Point 1 north of the border between Manitowoc and Kewaunee County. From Point 1 the boundary continues SSW in a straight line to Point 2 and then SW to Point 3 which is located in Lake Michigan approximately 16.3 miles east of a point on the shoreline roughly equidistant between the borders of northern Mequon, WI and southern Port Washington, WI. From Point 3 the boundary continues west towards Point 4 until it intersects the shoreline at the low water datum approximately 2.5 miles north of the northern border of Mequon, WI. From this intersection the boundary continues north following the shoreline at the low water datum, cutting across the mouths of creeks and streams until it intersects the line segment formed between Point 5 and Point 6 at the end of the southern breakwater at the mouth of Sauk Creek at Port Washington. From this intersection the boundary continues to Point 6 through Point 9 in numerical order. From Point 9 the boundary continues towards Point 10 until it intersects the shoreline at the low water datum at the end of the northern breakwater at the mouth of Sauk Creek. From this intersection the boundary continues north following the shoreline at the low water datum cutting across the mouths of creeks and streams until it intersects the line segment formed between Point 11 and Point 12 at the end of the southern breakwater at the mouth of the Sheboygan River. From this intersection the boundary continues to Point 12 through Point 17 in numerical order.

From Point 17 the boundary continues towards Point 18 until it intersects the shoreline at the low water datum at the end of the northern breakwater at the mouth of the Sheboygan River. From this intersection the boundary continues north along the shoreline at the low water datum cutting across the mouths of creeks and streams until it intersects the line segment formed between Point 19 and Point 20 at the end of the southern breakwater at the mouth of Manitowoc Harbor. From this intersection the boundary continues to Point 20 through Point 23 in numerical order. From Point 23 the boundary continues towards Point 24 until it intersects the shoreline at the low water datum at the end of the northern breakwater at the mouth of the Sheboygan River. From this intersection the boundary continues north following the shoreline at the low water datum cutting across the mouths of creeks and streams until it intersects the line segment formed between Point 25 and Point 26 at the end of the western breakwater at the mouth of East Twin River. From this intersection the boundary continues to Point 27 through Point 31 in numerical order.

From Point 31 the boundary continues towards Point 32 until it intersects the shoreline at the low water datum at the end of the eastern breakwater at the mouth of East Twin River. From this intersection the boundary continues NE following the shoreline at the low water datum cutting across the mouths of creeks and streams around Rawley Point and then continues NNW past the county border between Manitowoc and Kewaunee County until it intersects the line segment formed between Point 33 and Point 34 along the shoreline at the low water datum just south of the mouth of the unnamed stream near the intersection of Sandy Bar Road and Lakeview Road near Carlton, WI. Finally, from this intersection at the shoreline at the low water datum the boundary moves east across Lake Michigan to Point 34.