Due to the route the cable has to take between the mainland and the islands, a large number of cores had to be taken in deep water. Several of those cores were taken in water depths of over 200m and the deepest of all was some 220m. Excellent penetration and recovery was obtained at all depths (bedrock permitting) in material including clays, sands and angular gravels.

The work itself was carried out from a small, 15m multicat, with surveyors from Osiris Projects carrying out the vessel positioning and navigation. The compact vibrocore spread proved that it could work well within the constraints of a smaller vessel.

However, for jobs requiring greater sample depths, the flexibility of GTS Subsea's vibrocorer design means it can also be quickly configured to operate in longer modes (for example 6m).

GTS Subsea also put into service the first production run of its new, toughened, umbilical.

This latest addition to the equipment spread carries power conductors and four twisted pairs for bi-directional data, video and control signals to the corers. The umbilical proved very easy to manage, even during spring tides, and the jacket has shown itself to be extremely hardy.