The UK Ship Register (UKSR) has crashed out of the top 20 flags, dropping from 19th to 21st since August, overtaken by India and Iran.
UKSR has lost 234 vessels since the start of the year, including 53 boxships, equivalent to a 36% cut in the total gross tonnage of UK-flagged vessels.
The number of vessels switching flags in the first six months of 2019 is higher than the total de-flagged over the past three years – although 150 quit in 2015.
Uncertainty around Brexit and the requirement for vessel operators to comply with European Union maritime regulations appear to be the main reasons behind deflagging.
P&O Ferries has transferred five vessels to the Cyprus flag this year while CMA CGM has reflagged 46 of its 49 UK-registered boxships 'after it appeared that the UK flag was excluded from the draft agreement envisaged between the UK and the European Union'.
According to the Marseilles-based operator, 'in light of Brexit and despite a strong relationship with the UK Ship Register, and to avoid uncertainty with the fleet' it decided to transfer its UK-flagged vessels to Malta and RIF, France's second register, to keep tonnage tax advantages after the UK leaves the EU.