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.

"EPS is helped not only by lower fuel price per [available lower berth days] but also by lower consumption."

Carnival's shares gained 8.8% this morning to $50.49.

While maintaining a buy rating, UBS has risen its estimates by 16% to $0.77 for the second quarter, 3% to $2.84 for the third and and 15% to $0.97 for the fourth.

All of these forecasts surpass respective consensuses of $0.71, $2.73 and $0.86.

Only EPS forecast for this year's first quarter were lowered 8% to $0.44 due to delayed delivery of LNG-powered 6,600-berth AidaNova, launched in December a month behind schedule.

UBS has also lifted its takes for all of 2019 by 6% to $5.01, 2020 by 5% to $5.77 and 2021 by 4% to $6.72. These estimates also beat Wall Street's respective guesses of $4.76, $5.23 and $6.20.

UBS also notes that the Arnold Donald-led company's cumulative advanced bookings for 2019 are "considerably ahead" 2018 at in-line prices, driven by performance in the Caribbean.

"Caribbean is significantly better," Farley wrote.

She pointed out, however, that double-digit supply growth for Carnival's European brands has put a slight drag on yield guidance butNorth American demand for Europe stays strong.

"In fact, overall company pricing since September is in line with last year's levels yet CCL has a double-digit increase in bookings even while maintaining its price levels," she said.