Around Mack's home, tulips are blooming and seagulls are flying. People kayak past his window. Mack lives on a houseboat. Now 83, he has been floating on Seattle's Portage Bay since the Beatles released "Yellow Submarine." Each dock on Portage Bay has its own distinct character. Some have custom-made homes. Others look like suburban neighborhoods with potted flowers on their front porches and neighbors who look out for each other. Instead of a yard, they have a lake. Housing costs are skyrocketing throughout Seattle, and the city's iconic houseboat neighborhoods are no exception. Over the last half century, Mack has seen his surroundings change from affordable homes to million-dollar properties. 'Shanty Town' On Portage Bay

Mack, who asked that his last name not be used, has light blue eyes that match the water and a striking vitality. He came to Seattle in 1968 on a whim to visit his cousin and happened upon the houseboat community. Mack had been living overseas and decided to stay in Seattle for a week or two while he figured out what he wanted to do next. At that time, many people were selling their floating homes because they knew it would cost them as much as they'd paid for the house to put in sewer lines. "They were getting out, and that was a good deal for me," Mack explained. Back then, houseboats cost around $7,000, which was what he could afford. He used his savings from his time in the military to buy his home. People told him he wouldn't last more than a couple of years. When Mack first moved in, the floating home community was different than it is today. "Students on the other side, students down the way," he remembered, "people that were low or medium income. A few well to do, but not many. They didn't stay very long." A lot of the houses were poorly constructed, and the water surrounding them was filled with sewage. When Mack's father's came to visit, he was not impressed. "He said he got me through private schools and I ended up in a shanty town. He was not happy about it, so he never came back."

"That's OK," Mack said. "He did what he wanted to do, and I did what I needed to do." The city of Seattle wasn't enthusiastic about the houseboats, either. "We were considered dregs, I guess," said Mack, "and it was the citizens of Seattle that said wait a minute - we like those dregs. They're fun places. We like to bring our out-of-town guests to see the houseboat colonies." "So we began to clean up the lake," explained Mack, "and suddenly it became quite the place to live. After that it was changed." 'It's Happening All Over Seattle, Not Just Here' Prices for houseboats skyrocketed. Now a two-bedroom, two-bath home can top $975,000 - nearly 140 times the price Mack paid for his.

It took him years of repairs to make his houseboat into the home it is today. It's filled with objects from his travels and pieces salvaged from shipyards. His bed sits under the window. There's just enough space for one person to walk by. Mack stayed, while other owners drifted away. New owners moved in to take their places. Now many of the houseboats belong to the young and affluent, including tech workers. "It's getting different now," said Mack, "because they're coming in and thinking, 'what a good deal, we'll buy this and rent it out.' So you lose that continuity and I miss that." "But that's Seattle," he added. "It's happening all over Seattle, not just here." From Mack's back porch you can see construction cranes around the lake. The cityscape is changing. Some of the new houseboats are made of metal and look like they've come from a science fiction movie. There are homes with docks big enough to moor a yacht, and homes that have full rooftop gardens.