I don't have personal experience of any crewed catamarans in Croatia but I did bareboat from an excellent company last September. Here's a link to the company and a boat that might meet your needs... Croatia Yacht Charter They have skippers and hostesses available. The company and people were easy to deal with, very helpful with good spoken English and the 45ft cat I chartered was in excellent condition. Google does of course return many options for crewed charter but I cannot comment on the quality of any of those. Hope you find something.