Unfortunately, there are very few travel agencies and providers that have swinger cruises in their program. The best overview you can get on erotravel.de or swingerkreuzfahrten.com, there are most offers at a glance. Through these sites you can also book directly with the respective organizer. Since there are currently only American providers who organize trips in Europe or overseas, you can write to the site operator for German-speaking assistance with the booking and ask questions.