Norwegian Cruise Line stock is profitable today, but those profits are shrinking.Norwegian Cruise Line Holdings (NCLH 15.06%) stock tumbled 12.5% through 11:35 a.m. ET Tuesday after reporting mixed earnings this morning.Heading into the report, analysts forecast the cruise line would earn $1.16 per share (adjusted for one-time items) on$3 billion in quarterly sales. Norwegian beat the earnings forecast with a $1.20 (also non-GAAP) profit, but its sales were only$2.9 billion. Norwegian Cruise Q3 earningsM ...