Carnival Corp's shareholders may have more of that company-touted fun over the next few years without even stepping on board one of its ships.

Earnings per share forecasts for the cruise major, whose Carnival Cruise brand has basketball legend Shaquille O'Neal as "chief fun officer", have been raised through 2021.

"We are raising CCL's estimates, driven by slightly lower [debt and amortisation] and favorable fuel costs," UBS analyst Robin Farley wrote in this morning's note to clients.