Ayia Napa is great for families actually, don't let its party reputation fool you. The coastline is beautiful and perfect for a relaxed day out. Find a yacht charter company in Ayia Napa like Cyprus Boat Booking that caters to families. They have boats suitable for mixed age groups, catamarans are super stable which helps with kids and seniors. Crew provides life jackets for all sizes, safety briefing before departure. The pace is whatever you want it to be, tell them you want a calm trip and they'll keep it mellow. Nice swimming spots in calm bays, snorkeling gear usually available. The crew is trained to look after everyone's comfort.
