Once an aircraft has been located, an underwater survey is conducted before recovery operations begin.

I don't recall, but it certainly had to do with the underwater surveys.

The underwater survey commenced in April 2007 and took two and half years to complete.

The wreck will then probably be used as a training site for divers interested in learning the basic skills of underwater survey and drawing.

You conduct your underwater survey while the ship is docked in port.

This has also been confirmed by underwater surveys undertaken in the harbor, which have uncovered pottery characteristic of the period.

Since 1980 underwater surveys have also been taking place in the harbor.

Five years later, the first underwater survey was carried out.

From 2006 underwater archaeological surveys are regularly taking place in the area.

Coast Guard officials said that they were finishing underwater surveys of shipping channels.