Resting in 25 feet of water within Madeline Island's Big Bay in Lake Superior, approximately 300 feet east of Big Bay State Park, are the remains of a small unidentified sloop. Tentatively identified as a Huron boat following its discovery in the 1990s (a derivative of the Mackinaw boat), further work failed to positively identify the vessel type or name, but suggested the vessel is a type of vernacular sloop. The uncertainty in identifying the vessel type is due to an almost complete absence of either historical or contemporary documentation of small craft on the Great Lakes. The Big Bay Sloop is the only one of its type known to exist in Wisconsin waters, making it a significant archaeological resource. Sites like the Big Bay Sloop are vitally important to our understanding of the construction and use of historic small craft on the Great Lakes.

The sloop's construction and the history of the development of the Apostle Islands indicate a circa date of 1880-1920. Although small craft were common in the Apostle Islands region much earlier than 1880, the vessel's wire rigging and metal cleat place the use of this vessel nearer the turn of the century. The proximity of the vessel to an abandoned crib suggest it was in commercial use at the time of its loss, and by 1920 screw-powered vessels had largely supplanted sail power in small commercial watercraft.

State and federal laws protect this shipwreck. Divers may not remove artifacts or structure when visiting this shipwreck site. Removing, defacing, displacing or destroying artifacts or sites is a crime. More information on Wisconsin's historic shipwrecks may be found by visiting Wisconsin's Great Lakes Shipwrecks website.