The grounding of a Great Lakes bulker was caused by inadequate operating company guidance on under-keel clearance, the US National Transportation Safety Board (NTSB) has found.

American Steamship Co’s 33,400-dwt John J Boland (built 1973) was completing its final loading in Lake Huron when it grounded twice on 21 April 2023, the NTSB said in a report issued on Tuesday.