Yes, you can book portions of
around the world cruises.See them on Seaborn,Regent..but probably on many others.
Too me,that would be TOO LONG,,but to each his own.Have heard of people who book around the world tours and just live on boat year round. Cheaper than some nursing homes and much nicer,,if you re super rich,that is.;Can have room service,Dr. onboard,etc...what a way to go.