If you have to ask how much, you can't read the sign.

"$139,875," says the poster, unmistakably, next to the Chris Craft 381 Catalina Double Cabin Cruiser, 38 feet of nautical bliss at the Washington Convention Center.

"Shoes off, please," says the salesman politely. You'd think he was guarding a mosque.

"Or a Japanese restaurant," he says. Michael Yerman, a Baltimore businessman, emerges from the double cabin. "It's all Naugahyde inside," he marvels. "It's just like an RV."

An understandable confusion, considering that over in the next exhibition hall -- in the RV section of the 1985 Washington Recreational Vehicle and Outdoor Show -- they're calling the $156,000 Executive 40 a "land yacht."

"This one has a backup zero TV camera, two built-in color TVs front and back, built-in cable hookup, two stereos, central air conditioning you can have air in front and heat in back if you like , 54 cubic feet of storage, built-in telephone and -- young man, not with the ice cream," says the expansive salesman, Bob Culver, interrupting his peroration to caution a visitor against bringing gooey things inside the 40-foot dormeuse.

"The man who would buy this drives a Rolls-Royce, if you follow what I'm saying," Culver adds.

The show, which runs through Sunday, is billed by the sponsoring dealers as the biggest such display on the East Coast -- "the Super Bowl of 'RV' shows" -- and boasts more than 1,000 road vehicles and boats, not to mention accessories, running from a Yamaha Tri-Zinger three-wheeler to a 40-foot Hunter sloop. It covers 10 acres of four exhibition halls just across from the Greyhound bus station.

"We've got 22 million pounds of display worth about $25 million, which is a dollar a pound, as a rule of thumb," says Tom Stafford as he escorts a visitor past Clam Court, down Seagull Street and toward a Formica counter in the middle of a clump of palm fronds -- "We call it the Bahama Bar," he says jauntily. "I'd say we'll get about 70,000 people."

His company, Creative Promotions, put the show together. His lapel sports a button reading "Business Is Good."

It's especially good at radio station WCLY-FM's promotional display, a glass booth in the sailboat section swirling with U.S. currency. A crowd gathers as a young man enters the booth to flail for dollars.

"Just call us 'Classy 95,' " says disc jockey John Dowling, who is supervising the goings-on. "It's 'adult contemporary.' Make that 'personality adult contemporary.' "

There's a burst of applause. It turns out that the contestant, 23-year-old Scott Howell, has caught a flying $100 bill along with several crisp singles.

"I'm happy I came to this show," Howell ventures.

"I'll need to take down your Social Security number," Dowling says. He flashes a smile, but not a very big one.

Over on the other side of the hall, three guys drinking beer from plastic cups seem transfixed by a videotape about wind surfing. To the surge of mellow music, bikini-clad posteriors and sleek sailboards vie for the camera's attention amid crashing ocean waves.

"I haven't seen anything like this before," says Tom Zinn, 26, a computer program analyst for the Internal Revenue Service, staring dreamily. "I wonder if I can get a copy of this."

In the RV section -- easily identified by the proliferation of trail and river names affixed to painted wood representations of cactus -- the Skeiriks, a retired couple from Arlington, check out the mobile homes.

"We already have a Class C 23-foot Jamboree, but I think we want something bigger," says Kathryn Skeirik. "We just traveled the length of Skyline Drive, down to Atlanta, Georgia, and through the whole state of Florida."

"We want to see the country," says Kaleel Skeirik. "We want to go to Alaska, see the Northwest, New England, Acadia, Nova Scotia, the desert areas . . ."

And more than a few show-goers -- like Chris Rodriguez, 32, who has trekked down Florida's Tamiami Trail, across the Mississippi River and through the Grand Canyon in search of recreational perfection -- are irresistibly drawn to a sign that invites: BODY MAGIC Portable, battery-operated MASSAGE PILLOW BACK ACHE? FEET HURT? SIT DOWN AND TRY IT!

"Ah, that feels great," Rodriguez sighs.