I've been sent a few e-mails and PMs asking more about how the Illuminations cruise works, not how to get them.
There are 4 boats at this time of the year and 1 boat is located at Boardwalk and the others at the B/Y Club resort. It's a pantoon boat with cushioned seating on the left and right front of the boat and the back. I believe 3 adults on each side and maybe 4 adults in the back is about it for seating capacity. You may fit a little more with children or if all the adults are toothpicks. There are different opinions on seat capacity. This boat is open top. There's a breeze when moving on the water. The rule of thumb for departure is to be there to board at least 45 minutes before the schedule time of the fireworks show. You get a little cruising in before the show. You should check the schedule for fireworks to keep up to date on your time. Also, call back and confirm with Disney for exact time.
All the boats are lined up together for the show. You are located on one end of the lagoon, nearest to Canada. You can get special party packages at an extra cost (usually $100 more or so). I've seen cake and drinks with a decorated boat. Also, I've seen champagne (maybe non-alcoholic), whip cream, and strawberries (usually for honeymoon couples). I have not seen pizza but that may be possible, too. Maybe, others can share what they have seen or done.
Disney is a business and you have to understand that they are not going to cancel cruises because that means lost revenue. If it's drizzling rain the boat goes out. Towels have been passed out to dry the seats. If it's cold (December can have 40 degree nights) the boat goes out. Blankets have been provided in the past to keep warm. My answer in December is to come prepared with coat and umbrella, if needed.
MVMCP can have cold and rainy nights, too. Hot chocolate goes a long way on such nights.
Lightening and mechanical failure of the boat are the only reasons I know that Disney will cancel and refund monies for the cruise. Once the boat leaves the dock I'm not aware of any refunds for any other reasons. If there's a technical problem with Illuminations and no fireworks, you still pay for the cruise. It's not an iron clad guarantee that you get to see fireworks. I don't think it happens often but some problems are out of Disney's control. Maybe others who have been through some weather or technical problems can share what happened to them.
Even with risks listed above I would not pass up the opportunity to do a cruise at least once. I'm hooked and we go on every trip, now. It's almost always the highlight of our trip. It's great not to wait at Epcot and fight the crowds. It's also great not to fight the crowds getting out of the park after the show, either.
Sharing a cruise keeps cost down, if that's a concern. It's a wonderful way to meet fellow, DisBoard members, too. I hope I've helped a few out there understand the cruises a little better. Maybe, a few others can add or subtract from what I've said.
The cruise is going to run $120 + tax and gratuity. I figure that means about $155 total.
Mickey
Oh well, that just means I'll have to schedule another trip soon and try again! 
last year for our anniversary and loved 
