In Spain, six vessels were frozen following sanctions imposed after Russia's invasion of Ukraine in February.
The "majority" of the owners are paying their maintenance, crew, docking and insurance fees, a source with knowledge of the matter said.
In March, Spain's Prime Minister Pedro Sanchez vowed, when announcing the freezing of one yacht in Spain, to hit Putin's allies "decisively" and "hard".
read more read moreProposals by the United States and European Union to sell seized Russian assets and give the proceeds to Ukraine have stalled.
In France, five yachts have been frozen.