Shotline Diving Wreck Profile
- Name: USCGC Mesquite (WLB-305)
- Type: U.S. Coast Guard Cutter – Seagoing Buoy Tender (WLB-180 class)
- Year Built: 1943
- Builder: Marine Iron and Shipbuilding Company, Duluth, Minnesota
- Dimensions: 180 ft (54.9 m) length; 37 ft (11.3 m) beam; 12 ft (3.7 m) draft
- Registered Tonnage:
- Depth at Wreck Site: 25 m / 82 ft
- Location: Keystone Bay, off Keweenaw Peninsula
- Coordinates: 47° 23.440' N 87° 44.530' W
- Official Number: WLB-305
- Original Owners: United States Coast Guard
Wreck Location Map
Vessel Type
USCGC Mesquite was a 180-foot Iris-class seagoing buoy tender. Built with a steel hull and diesel-electric propulsion, she was designed for year-round navigation aid deployment, icebreaking, firefighting, and rescue duties on the Great Lakes.
Description
Commissioned in 1943, Mesquite served during WWII in the Pacific and then operated from Sault Ste. Marie, MI. On December 4, 1989, while recovering buoys, she grounded on a shoal off Keweenaw Point. Unable to be salvaged due to severe winter storms, she was later declared a total loss.
History
In July 1990, Mesquite was intentionally scuttled as an artificial reef and dive site in Keystone Bay. Her final depth ranges from 82 to 112 feet, resting upright and largely intact within the Keweenaw Underwater Preserve.
Significant Incidents
- Grounded on a shoal off Keweenaw Point on December 4, 1989, while recovering buoys.
- Declared a total loss due to inability to salvage amidst severe winter storms.
Final Disposition
Mesquite’s wreck location was designated and placed intentionally; it is not a lost wreck. Her position is maintained by the Michigan Department of Natural Resources and local dive groups.
Current Condition & Accessibility
All 50 crew survived with minor injuries. No casualties reported. The site lies in preserved waters; artifact removal is prohibited. Divers are encouraged to practice no-touch documentation methods and to leave the site better than they found it.
Resources & Links
[shotline_reference_links slug=”u-s-coast-guard-cutter-mesquite” title=”References & Links” show_ref_button=”yes”]
For divers, the USCGC Mesquite offers a unique opportunity to explore a significant piece of maritime history while adhering to ethical diving practices. Remember to leave only bubbles and take only memories.
Legacy Notes & Full Historical Record
This section preserves the original unedited Shotline content for this wreck so that no historical detail is lost as we transition to the new logbook format.
Identification Card (Site Style)
Type: U.S. Coast Guard Cutter – Seagoing Buoy Tender (WLB-180 class)
Builder: Marine Iron and Shipbuilding Company, Duluth, Minnesota
Build Year: 1943
Construction Location: Duluth, Minnesota, USA
Dimensions: 54.9 m (180 ft) length; 11.3 m (37 ft) beam; 3.7 m (12 ft) draft
Propulsion: Diesel-electric
Cargo on Final Voyage: Navigational buoys and tackle
Date of Loss: December 4, 1989
Location: Keystone Bay, off Keweenaw Peninsula, Lake Superior
Coordinates: 82′112′N 47° 23.440 W 087° 44.530
Depth: 25–34 m (82–112 ft)
Owners: United States Coast Guard
Home Port: Sault Ste. Marie, Michigan
Description
USCGC Mesquite was a 180-foot Iris-class seagoing buoy tender. Built with a steel hull and diesel-electric propulsion, she was designed for year-round navigation aid deployment, icebreaking, firefighting, and rescue duties on the Great Lakes.
History
Commissioned in 1943, Mesquite served during WWII in the Pacific and then operated from Sault Ste. Marie, MI. On December 4, 1989, while recovering buoys, she grounded on a shoal off Keweenaw Point. Unable to be salvaged due to severe winter storms, she was later declared a total loss.
Final Disposition
In July 1990, Mesquite was intentionally scuttled as an artificial reef and dive site in Keystone Bay. Her final depth ranges from 82 to 112 feet, resting upright and largely intact within the Keweenaw Underwater Preserve.
Located By & Date Found
Mesquite’s wreck location was designated and placed intentionally; it is not a lost wreck. Her position is maintained by the Michigan Department of Natural Resources and local dive groups.
Notmars & Advisories
No active NOTMARs noted. Site lies in preserved waters; artifact removal is prohibited.
Dive Information
- Access Type: Boat
- Entry Point: Copper Harbor or Eagle Harbor
- Conditions: Cold (4°C/40°F), low currents, excellent visibility
- Depth Range: 25–34 m (82–112 ft)
- Emergency Contacts: USCG Sector Sault Ste. Marie
- Permits: None required; site is within public preserve
Crew & Casualty Memorials
All 50 crew survived with minor injuries. No casualties reported. No formal memorial markers on-site.
Documented Statements & Extracts
“The Mesquite grounded in 12 feet of water while recovering the last buoy of the season… she was a total loss by morning.” — TV6 Marquette
Registry, Enrollment & Insurance Trails
- USCG Number: WLB-305
- Registry: U.S. Coast Guard
- Archives: USCG Historian’s Office
Site Documentation & Imaging
Resources & Links
References
NOAA/WHS Shipwreck Record Card
Other Names: WLB-305
Coordinates: Undisclosed
Depth: 82–112 ft
Location: Keystone Bay, Keweenaw Underwater Preserve
Type: Buoy Tender, Iris-class
Material: Steel
Dimensions: 180 ft x 37 ft x 12 ft
Condition: Upright, intact
Cause of Loss: Grounded on shoal
Discovery Date: July 1990
Discovered By: USCG & DNR
Method: Controlled scuttling
Legal Status: Protected
Hazards: Cold temperatures
Permits: Not required for non-commercial diving