Identify an unknown shipwreck
Work through a real example: how Port Gregory’s “boiler wreck” became a supported identification of SS Xantho.
Before you start
- A scaled wreck model with an editable annotation layer.
- Survey notes, candidate records, plans or photographs to compare with the site.
- A signed-in organisation account to create or edit annotations.
Start with the field description
In 1979 local knowledge led volunteer divers to an iron site at Port Gregory known as the “boiler wreck”. Begin there: iron wreck, Port Gregory, prominent boiler. Do not begin by labelling every feature Xantho. In your own room, title the investigation with the place and observable site type until the evidence supports more.
- Observed
- Iron wreck with a prominent boiler
- Location
- Port Gregory
- Question
- Does the site fit SS Xantho better than another vessel?
Map the diagnostic machinery
Survey the whole model, then annotate the boiler, engine position, thrust block, shaft line, propeller and surviving stern structure. Measure their spacing and orientation where the model supports it. These linked features describe a propulsion system. That pattern is stronger evidence than one isolated object.
Compare the site with the candidate
The WA Museum record gives Xantho as an iron steamship 34.7 m long and 5.4 m in beam, lost at Port Gregory in 1872. Its unusual refit replaced paddle machinery with screw propulsion and a horizontal trunk engine. Compare the model’s dimensions and machinery arrangement against those particulars. Record a mismatch as carefully as a match.
- Site
- Boiler, screw-propulsion machinery and stern survive together
- Record
- 34.7 m × 5.4 m iron steamer, lost at Port Gregory
- Diagnostic
- Rare horizontal trunk engine in a converted paddle steamer
Use close evidence to strengthen the result
Excavation exposed a maker’s plate reading John Penn and Son, Greenwich, and numbered engine components. Those details tied the unusual machinery to the documented refit far more securely than the boiler alone. In BelowVR, put the observation in the annotation title and the interpretation, source and uncertainty in its note.
Continue when: Another person can open each marker and see what was observed, what it may mean, and where the comparison came from.
State the identification as an argument
Conclude with the chain: location and vessel type fit; dimensions and propulsion layout fit; the rare engine and maker evidence are highly diagnostic; no stronger contradictory candidate explains the site. Finish with confidence, remaining uncertainty and the next check. BelowVR holds the spatial argument; the responsible authority makes the formal identification.