Here's a boat you probably didn't get to see in your travels among the numerous sites at the recently concluded Fort Lauderdale International Boat Show -- the new Triumph Skiff 1700. That's because the company didn't have exhibit space or a local dealer. To get the word out about the newest model of what Triumph bills as ''the world's toughest boat,'' company representatives Mark Welsh and Jeff Gross gave demo rides to a handful of boating writers on the Intracoastal Waterway in Fort Lauderdale.