Gerardus Chapel was at the helm of the 8,400-dwt hopper vessel Shoreway (built 2009) on 8 June when it collided with a yacht called Orca at the entrance to the River Orwell in Suffolk.
It had just finished dredging in Felixstowe and was going out to sea to dump its cargo.
The Maritime and Coastguard Agency said for an "unknown reason" it left the deep water channel and headed into an area frequented by pleasure vessels.
Shoreway
