The BJ tournaments on CCL have a $20 entry fee and you can enter as often as you like. They play 6 players to a table and play 7 hands for each table. Player with the most chips at the end of the 7 hands wins. Then that player's name and total goes onto the leader board if their total is greater than the best seven totals. So you are really playing against everyone that enters. So you can't just play to beat the current table, you have to play to rack up enough points to get on the board to get a spot at the final table. The final table you only have to beat the other players at the table to win it all. ITs not a BAD format, but I would like to see them play more than 7 hands. It doesn't take much of a bad card streak to kill your total in 7 hands.
Yes, they have a $3 minium table on the first day of the cruise. Then they typically have at least one $5 table open and then depending on the crowd, they will open $10 and $25 tables.
Craps on Carnival is 2x odds, on RCCL the craps table was one 1x odds (which is almost pointless) but they did have one night where they played 2X odds. CCL also has Let it Ride, three card poker, caribbean stud and roulette along with slots. The bigger ships have a hold-em table (the Spirit and the Conquest have one but I can't speak for the rest of the fleet)
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise, Magic 1/14
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013