Shotline Diving

Connecting You to the Depths of the Great Lakes

Mary Alice B (Quintus, Bonanka, Lomax)

Explore the submerged wreck of the Mary Alice B, a tugboat sunk in 1975, posing a navigational hazard in Lake Huron near Port Sanilac.

Shotline Diving Wreck Profile

  • Name: Mary Alice B
  • Type: Tugboat
  • Year Built:
  • Builder:
  • Dimensions: 45 ft (13.72 m); Beam; Depth of hold
  • Registered Tonnage:
  • Depth at Wreck Site: 23 m / 75 ft
  • Location: Lake Huron, off Port Sanilac, Michigan
  • Coordinates: Latitude 4320'18N, Longitude 8226'24W

Wreck Location Map

Vessel Type

The Mary Alice B was a 45-foot tugboat built to assist larger vessels on the Great Lakes. Tugboats of this size were critical to maritime operations, particularly in harbors and high-traffic shipping routes. Known for their reliability and robust construction, tugboats like the Mary Alice B were essential to maintaining the flow of commercial and industrial shipping during the mid-20th century.

Description

The Mary Alice B sank in 1975, with the incident first reported in the Local Notice to Mariners (LNM) number 72/75 on September 10, 1975. The exact cause of the sinking remains unclear, but its loss marked the tugboat as a notable navigational hazard.

The wreck lies submerged off Port Sanilac, Michigan, in Lake Huron, at a depth of approximately 75 feet (23 meters). Its reported position is of moderate accuracy, noted as “Medium quality” in historical records. Parts of the wreckage may rest near or at the water’s surface, posing a significant hazard to vessels unaware of its presence. The site’s classification as a danger to surface navigation underscores the potential risk it continues to pose decades after its sinking.

History

The wreck rests submerged near Port Sanilac in Lake Huron, at coordinates 4320’18N, 8226’24W, and a depth of 75 feet. Its hazardous classification suggests that some parts of the wreck extend upward, close to the surface, making it especially dangerous to surface navigation.

Significant Incidents

  • No recorded salvage operations for the Mary Alice B following its sinking.
  • The lack of intervention has resulted in the wreck remaining a persistent hazard to surface vessels.
  • Monitoring the wreck for position changes or structural deterioration is recommended to mitigate future risks.

Final Disposition

The Mary Alice B exemplifies the dangers posed by shipwrecks, even long after their sinking. The site off Port Sanilac remains hazardous due to its proximity to the water’s surface, demanding caution from mariners navigating Lake Huron. This wreck is a significant navigational concern and serves as a reminder of the need for vigilance in areas with known submerged hazards.

Current Condition & Accessibility

Mariners and authorities are advised to exercise caution in the vicinity due to the wreck’s hazard classification. Further surveys or monitoring may be warranted to ensure continued maritime safety.

Resources & Links

For divers, the Mary Alice B offers a unique opportunity to explore a historical wreck while practicing responsible diving. Remember to leave only bubbles and take only memories, ensuring the site remains undisturbed for future generations.