Because "when you are used to living in a palace with dozens of servants, you don't want to cruise the oceans on a small yacht." That's how Berkeley March, the naval architect of the world's largest private boat justified his plans, unveiled yesterday in London. The 656-foot vessel is 99 feet longer than the current longest yacht, and features a two-level movie theater, a nightclub, a casino, a helipad -- and an eight-figure price tag. That price could go even higher if the buyer has special requests like "gold furniture," explained March, who believes the recession has actually created the perfect climate for selling such an item. "The people left with a lot of money have more power now, as there is less demand."