Sportsman Boats Manufacturing announced that it plans to create another 100 jobs and invest $3.5 million at its Dorchester County site to keep up with demand.

The company said it will be adding 70,000 square feet of production space to its Limbros Industrial Park site to accommodate growth in its upholstery, welding and fabrication operations.

 It expects its payroll to swell to about 370 workers, with hiring for the new openings already underway.

Sportsman Boats is headquartered on Isaac Way, off U.S. Highway 78, where it recently installed an 800-kilowatt rooftop solar power system as part of its sustainability efforts.

The company said it now makes 21 models of saltwater center-console fishing and bay boats ranging in length from 17 to 31 feet. They are now carried by about 50 dealers. The company also has started selling in the international market.

The S.C. Coordinating Council for Economic Development has approved state tax credits that Sportsman Boats can apply for in the future, based on the number of jobs it creates under the new expansion.

The company was started with six employees in 2011 by two former founders of Sea Pro Boats in the Midlands and Key West Boats in Summerville who were itching to get back into the industry as sales started to bounce back from the recession.

Two years ago, Sportsman announced it would more than double the size of its plant by adding 116,000 square feet of space. The $3.5 million investment also called for the creation of 150 jobs.

 The company announced a smaller expansion in 2013.

“Sportsman Boats is proud to have roots here in South Carolina and Dorchester County, and we are excited about our continued growth,” said Tommy Hancock, co-founder and president.

The Summerville area is a longtime hub for boat makers, a lineup that includes Key West, Zodiac of North America and Scout.

The industry, which was hit hard by the last economic downturn, is now cruising along on a rising tide.

The National Marine Manufacturers Association estimated that sales of new powerboats climbed 6 percent to 7 percent to 250,000 units last year, a trend the trade group expects to continue through at least 2018.

“Economic indicators are working in the industry’s favor — a continuously improving housing market, strong consumer confidence, growing disposable income and consumer spending, and low interest rates all contribute to a healthy recreational boating market,” said Thom Dammrich, president of the association.