Cruises are about much more than sailing on rivers and seas

Underwater sightseeing in a glass submarine, shopping with a chef for dinner ingredients and volunteering with locals: These are some of the new options this season for cruise passengers.

Also in 2016 from the cruise industry, Royal Caribbean launches the world's largest ship, and a new ship from Carnival features a biking track suspended high above the water. And for cruisers with deep pockets, luxuries range from round-the-clock personal assistants to long-term leases for residences at sea.

Here are some details and other cruise news.