Drinks at the Sugarcane Mojito Bar on Norwegian Pearl

(4:25 p.m. EDT) -- For the first time in 18 months, Norwegian Cruise Line has raised the price of its Ultimate Beverage Package (UBP). The increase of nearly 13 percent makes it the most expensive alcohol package in the industry for a mainstream line.

The new cost, effective September 29, is $89 ($105 including an 18 percent gratuity) per person, per day, and includes unlimited fountain soda, spirits, draft and bottled beer, wines by the glass and cocktails up to $15, plus a 20 percent discount on bottles of wine. (It still does not include bottled water or specialty coffee beverages.)

The package also can be used for drinks on Great Stirrup Cay, the line's private island, and it allows passengers to order two drinks in one transaction, up from just one drink under the previous terms. All adults staying in the same cabin must purchase the package if one person does.

Anyone who purchased the UBP prior to September 29 is grandfathered in at the old price.

Pricing for the Corks and Caps package and the standard soda package remains the same at $59 per person, per day, and $7.50 per person, per day, respectively.

The last time the line raised prices for the UBP was in March 2016, when the daily cost went from $69 to $79 per person.

"... pricing may change from time to time due to costs increases and other factors," Norwegian said in a statement.

Members on the Cruise Critic message boards are discussing the issue, and few are pleased.

"They are out of their flipping minds," says member purpletequila. "What is that? About a 13 percent increase with no additional return ... ? I do like the NCL product, but there is no way ... I am consuming $105 a day in alcohol."

"I'd say 95 percent of people can't drink that much," notes OrlandoSingleCruiser. "Even during my college days I couldn't drink that much."

But CruisingUS has a different take, regarding the cruise line's use of the UBP as a booking promotion to entice cruisers: "Face it. most people get the UBP as a free perk. ... very few people pay for it in full."

Over the past two years, the line raised the cost of its dining package and its gratuities, which it raised twice within a five-month span in 2015 and again in early 2017.

Less than two weeks ago, Princess also increased the price of its alcohol-inclusive packages.

--By Ashley Kosciolek, Editor