A large number of vessels may face navigational problems or breakdowns if the shipping industry makes the fuel switch to meet IMO's sulphur cap without testing and going through a transition period, a major Greek owner said.

Nikolas Tsakos, chief executive of Tsakos Energy Navigation (TEN), warned of a repeat of the danger of fuel contamination that reared its head this year in Houston and Singapore, denouncing the lack of responsibility even though more than 120 vessels were impacted.