A US judge’s decision to slap BP with a finding of gross negligence in the Deepwater Horizon oil spill case could have a ripple effect on shipowners, maritime lawyers say.

Last week’s decision by District Judge Carl Barbier exposes the UK-headquartered energy giant to up to $18bn in fines for the 2010 drillship incident because, under the same US laws that cover tanker spills, civil penalties are quadrupled in cases of gross negligence compared with “ordinary negligence”.