Contract for Services in Relation to the Protection of Wrecks Act (1973): Diving investigations on the wreck of the Invincible.
Wessex Archaeology, 2012. https://doi.org/10.5284/1017436. How to cite using this DOI
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This work is licensed under the ADS Terms of Use and Access.
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Resource identifiers
- ADS Collection: 1151
- DOI:https://doi.org/10.5284/1017436
- How to cite using this DOI
Overview
The digital archive for this project submitted to the Archaeology Data Service consists of the following files:
- Archaeological Assessment Report
- A database recording the Diving information from the wreck of The Invincible
- Tracking data from four dives by a Remotely Operated Vehicle (ROV) or diver
- 120 images from four separate dives
- GIS shapefiles of the dive tracks
There is data from a total of six dives on the HMS Invincible, there are images from four dives, GIS shapefiles for six and dive tracking data for four. The 'DIVA' database contains dive summary information for some additional dives as well.
The Acoustic Tracking System
The Prospector acoustic tacking system (previously known as ROV-track) was used. Prospector is a Long Baseline (LBL) acoustic positioning system which uses a calibrated array of four acoustic transponder beacons on the seabed to track the diver. The beacons are deployed on the seabed in a rectangular array, weighted by biodegradable sandbags and buoyed upright by small subsurface floats.
The beacons are then calibrated by sailing around the array with a vessel-mounted acoustic transceiver below the waterline. The position of the array is established using a combination of surface position measurements from the vessel's DGPS and acoustic range measurements which are transmitted by the transceiver and reflected back by the beacons.
Once calibrated, the positions of the beacons are fixed and the diver can be tracked while wearing the transceiver without the need for further DGPS input.
Digital Photography
Digital still photographs were taken using a housed Canon G2 digital camera with a 0.56 wide-angle adapter using natural light only or, where necessary a single arm-mounted strobe with diffuser.
Digital Video
Video footage is recorded using a diver hat-mounted Colourwatch 306 single chip digital colour inspection camera and umbilical, recording onto mini-DV digital video tape. The entire duration of each dive is recorded. Post-survey stills are generated from the video. Wessex Archaeology retains the mini-DV digital video tape.
