The idle containership fleet has increased as a result of vessels having scrubbers retrofitted.
There were 118 vessels out of action on 8 July, Alphaliner said.
They account for 371,680 teu, with a "steady stream" of ships entering shipyards to have exhaust gas cleaners fitted, it added.
Alphaliner counts vessels as idle from day one if the work is being carried out separate from routine repairs.
