ROV Operations

The Remotely Operated Vehicle (ROV) survey of shallow wreck sites took place between the 11 and 26 June 2005. The survey was carried out from the MV Flatholm, Coastline Survey with two Wessex Archaeology staff acting as archaeological supervisor / tender and recording system operator to carry out the recording, and an external ROV operator.

The ROV and pilot were supplied by SUBCO Underwater Equipment. A Seaeye 600 high power inspection and observation ROV was used throughout the project.

The 1m long and 76cm wide ROV weighed 75kg. It was powered by 4 thrusters which provided a maximum forward speed of 2.5 knots. The ROV was supplied with 150m of umbilical. The maximum payload was 10kg.

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The ROV had two integrated cameras: a PAL colour camera; and a low light black and white (B/W) camera. Two 150 watt lights were dimmable and could be tilted together with the cameras to ± 80 degrees.

The ROV was equipped with forward scanning sonar for navigation, a built in fluxgate compass and a digital depth gauge. Information from these instruments could be displayed over the video output.

The surface controls consisted of an isolation transformer, the main ROV surface unit for power distribution, a hand controller with joystick, two screens and a Panasonic digital video capture unit. Video was recorded on miniDV tapes.

The ROV surface unit was installed in the survey container on deck. The umbilical was stowed on deck. Even though the ROV could be safely handled manually it was usually launched and recovered with the crane on deck.