I just went on an Illuminations cruise. The boats are docked at the Yacht club marina. You go on a relaxing boat ride and then park in a very advantageous spot to view the Illuminations show and fireworks. It is weather permitting. The nice thing about it is that you don't need park admission to see the show and after the fireworks, you are not dealing with throngs of people because you are outside of Epcot. Our captain was a long-time WDW employee and imparted a wealth of little-known facts and info about Disney. It was fun and different and refreshing not to be squeezed by crowds.
On the downside, it is pricey. But the boat seats up to 10, so the more people you bring, the more you will feel like you got your money's worth. You must book your cruise months in advance. And if you are not renting a car, you will have to take the bus from the Yacht club back to DT Disney and then another bus back to your resort which is time consuming. We actually took a cab which was about $10 plus tip from the Yacht club back to the POP and saved ourselves the aggravation.
We toured Epcot the next night, and since we had already seen Illuminations from the best vantage point there is, we skipped out just before it started and beat the rush back to the busses. It worked out great for us.