Defender Industries said Thursday that sales in September rose 12.9 percent and third-quarter sales rose 9.2 percent.

The Waterford, Conn.-based marine supplier also said sales for the first three quarters this year rose 18.6 percent from record 2009 levels.

Privately-held Defender does not release specific financial information, the company said.

“Boaters are spending money on their boats,” executive director Al Knupp said. “They’re just being more careful about how and where they spend it. Price matters, but they want the best overall value from someone they know and trust, and who has what they want.”

By mid-October, Knupp said, Defender’s sales for the year had surpassed the total for all of last year.

“This already makes 2010 the seventh consecutive year of record sales and the best in Defender’s 72-year history,” he added.

Knupp said he expects a sales increase of about 16 percent for the full year.