Deep Wreck Site WA1002

Side Scan of Steamer Wreck (40m x 6m x 4m)Side Scan of Steamer Wreck (40m x 6m x 4m)Wreck WA1002 was described by the UKHO as lying on its starboard side, with its bow to the southwest and mast lying alongside the wreck. The charted minimum depth over the site is 49m with the surrounding seafloor 60m deep.
 
The centre of the wreck was located using the sidescan sonar and found to be approximately 15m NE from its recorded position.
 

Detailed Results

Sidescan Sonar and Magnetometer Data

Side Scan of Whole SiteSide Scan of Whole SiteThe sidescan sonar data consisted of 11 lines, each approximately 800m long and orientated E-W with a 75m range setting. The area covered was approximately 800m x 350m. A further seven lines orientated NE-SW were surveyed along the length of the wreck. Forty-five sidescan sonar anomalies were identified.
 
After the sidescan sonar survey, magnetometer survey lines were acquired over the wreck site. The survey lines for this were orientated N-S. One magnetic anomaly was identified.
 
The 45 sidescan sonar and the magnetic anomalies were viewed in the GIS and grouped into seven sites. Again, each was given a level of Archaeological Potential:
 
Archaeological PotentialNumber within Study Area
High1
Medium2
Low4
Very Low0
Archaeological Potential Rating of geophysical anomalies within the WA1002 Study Area

The wreck is lying one its side in one piece (WA6200) and measures approximately 73m x 7m. It stands up to 7m above the seafloor. While it is difficult to determine which end is the bow, it is thought likely that it is to the south-west which implies that the wreck is lying on its starboard side. This agrees with the UKHO record.

 
Magnetometer ResultsMagnetometer ResultsThe sidescan sonar data show considerable evidence of structure remaining on the wreck although only one image shows an object that could be the mast recorded as lying alongside the wreck by the UKHO. To the stern of the wreck is a large structure that may be an A-frame and which could be an indication of the type of vessel.
 
This site (WA6200) has a magnetic anomaly of 1312.49nT, which confirms that the vessel is metal. The size of the magnetic anomaly produced by the wreck obscures any other smaller magnetic anomalies that may lie nearby.
 
Although wreck WA6200 appears intact, there are six sites around it, one of which is 230m away, which are interpreted as associated debris.
 

Multibeam Data

The multibeam data covers an area of approximately 1000m x 460m with the depth ranging from 52m to 60m. The Reson 8125 used for this project has a beamwidth of 0.5° and therefore the footprint of the beams over this site was approximately 0.8m.
 
Multibeam ResultsMultibeam ResultsThe main wreck site (WA6200) was located within the multibeam data only a few metres from the position as determined using the sidescan sonar data. The multibeam data shows that the wreck is approximately 63m x 10m x 8m.
 
The width and height are very similar to those recorded in the sidescan sonar survey but there is a large difference between the length measurements. The length of the wreck as measured from the sidescan sonar data ranged from 58m to 73m but the multibeam measurement of 63m is likely to be the most accurate.
 
From both the sidescan sonar and multibeam data sets, it can clearly be seen that a section of the hull is either damaged or missing from the midships area of the wreck. It is not possible to determine from the geophysical surveys whether the damage was caused at or shortly after the time that the ship sunk or by the deterioration of the hull on the seafloor.
 
Viewing the raw soundings rather than the gridded surface did not provide any further detail that would help in the identification of the vessel, but it did show that a large amount of sediment had built up against it, covering a large portion of the deck.
 
For information on the ROV survey of this site click here.