Shotline Diving Wreck Profile
- Name: Unknown 17
- Type: Harbor tug
- Year Built:
- Builder: Unknown—no registry plates or builder’s marks identified
- Dimensions: Approximately 40 ft (~12.2 m); Beam & Draft unknown
- Registered Tonnage:
- Depth at Wreck Site: 10 m / 33 ft
- Location: Thunder Bay “ship graveyard,” off Mission Island
Wreck Location Map
Vessel Type
Vessel Type
Harbor tug.
Description
Description
Unknown 17 is a compact wooden tug, approximately 40 feet in length, designed for harbor operations. The vessel is upright and intact below the waterline, although its upper structures have been removed or decayed.
History
History
As a compact wooden tug, Unknown 17 likely supported harbor operations—assisting ships in docking, towing scows, or moving barge lines before being retired. Its presence in the Thunder Bay scuttling zone preserves a rare example of small harbor workboat infrastructure.
Significant Incidents
Significant Incidents
- Deliberately scuttled, likely after decommissioning or as part of harbor clearance.
Final Disposition
Final Disposition
The vessel was scuttled in the Thunder Bay ship graveyard, where it remains submerged in a cold, low-silt environment that aids in the preservation of submerged wooden elements.
Current Condition & Accessibility
Current Condition & Accessibility
The hull is upright and intact below the waterline, with visible features such as likely engine bed mounts and tow post foundations. The site is accessible for diving, with typical depths ranging from 10 to 18 meters (33 to 60 feet).
Resources & Links
[shotline_reference_links slug=”unknown-17-tug-2″ title=”References & Links”]
Closing Summary
Documentation of Unknown 17 could reveal building practices, propulsion system type, and the life cycle of early Great Lakes tug vessels, contributing to the understanding of maritime history in the region.
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.
Site Identification
- Designation: Unknown 17 (per Thunder Bay wreck logs)
- Vessel Type: Harbor tug
- Construction Date: Not determined (n.d.)
- Material: Wood
- Estimated Length: ~40 ft
- Beam & Draft: Unknown—likely compact given size and tug function
- Builder/Origin: Unknown—no registry plates or builder’s marks identified
Wreck Site & Disposition
- Location: Thunder Bay “ship graveyard,” off Mission Island, Lake Superior
- Depth: Approximately 10–18 m (33–60 ft), typical zone for scuttled vessels
- Status: Deliberately scuttled, likely after decommissioning or as part of harbor clearance
Structural & Archaeological Description
- Hull Condition: Upright and intact below the waterline; upper structures removed or decayed
- Hull Layout: Compact and heavily framed in the stern—typical for towing power and machinery support
- Visible Features: Likely engine bed mounts and tow post foundations remain; fasteners possibly in place
- Preservation: Cold, low-silt environment aids in resilience of submerged wooden elements
Research Potential & Next Steps
| Objective | Suggested Action |
|---|---|
| Photogrammetric Recording | Document the hull form, stern framing, and possible engine bedlay using 3D underwater photogrammetry |
| Structural Analysis | Measure framing spacing and layout to compare with known 40‑ft wooden tug designs |
| Machinery Remnant Inspection | Search near engine bed for ballast blocks or alignment plates that indicate past machinery presence |
| Archival Tug Fleet Search | Cross-reference Thunder Bay and Port Arthur tug registries (late 1800s–1930s) for vessels ~40 ft in length |
| Timber Sampling | Use small-core dendrochronology tests to approximate age and hardwood species (e.g., oak, pine) used in tug construction |
Historical & Archaeological Significance
As a compact wooden tug, Unknown 17 likely supported harbor operations—assisting ships in docking, towing scows, or moving barge lines before being retired. Its presence in the Thunder Bay scuttling zone preserves a rare example of small harbor workboat infrastructure. Detailed documentation could reveal building practices, propulsion system type, and life cycle of early Great Lakes tug vessels.
unknown-17-tug 1936-07-21 00:20:00