Cruise line shareholders can access exclusive onboard credits, turning your investment in cruise stocks into discounts at sea ...

Living on a mass-market cruise ship can start at about $35,000 per year for room and board. Additional expenses include medical costs, laundry and alcohol, which can increase the overall cost.

Royal Caribbean celebrated its loyalest passenger earlier this month, a Cuban national named Mario Salcedo who's been living on the company's cruise ships permanently for nearly 25 years.

Each cruise line has its own system for distributing rewards ... same perks as Pearl and other preceding levels, plus exclusive benefits like $1,000 in onboard credit and a $500 shore excursion ...

Though the ship's name is rooted in the cruise line's past ... Members can receive benefits such as a complimentary stateroom upgrade, a dedicated concierge hotline and skip-the-line priority ...