Since 1999, divers have excavated at Bouldnor every year. Further discoveries were made at BC 2 and BC 4, and a later a new site was discovered nearby (BC 5). The dangerous diving conditions in the fast flowing waters of the Solent make archaeological investigation particularly difficult and archaeologists have used several new techniques to make analysis of the sea bed easier. This has included 'box sampling' – collecting large areas of sea bed in metal tins to raise them to the surface and more thoroughly excavate their contents on dry land.