There honestly aren't enough submarines in everyday life. Don't give me that their cramped or uncomfortable. They're awesome. So, with a child's eyes, wouldn't you want to live in one? Work in one? Or maybe buy cool shit in one?
John McCambridge and his art partner Jay Nelson came up with the idea for "Mollusk at Voyager" almost as a flight of fancy. Because why not buy shirts and surfboards in a big wooden submarine? It's part of the larger Voyager mall in the Mission district of San Francisco, serving as something of a "permanent street fair." It even has a periscope:
They started by using 2×2′s to construct the shell of the sub, inspired by the skeleton of a whale... The sub is lined with windows, which look out into a blue painted wall that really makes it feel like you're underwater. There's a hatch on the top, and a bunk bed along the left side of the sub. Dominating the interior is a periscope, which you can (and should) look into.