ROCKLAND, Maine — The streets of downtown Rockland echoed with the sounds of the blues Saturday and Sunday as thousands of spectators turned out for the North Atlantic Blues Festival despite gray skies and sometimes soggy conditions.

The annual festival typically draws about 8,000 spectators each day to hear top blues acts from around the country and the world perform against the scenic backdrop of Rockland Harbor.

After a fairly dry and unexpectedly pleasant day on Saturday, the sailboats and lobster boats docked in the harbor Sunday morning were largely shrouded by a thick fog as rain began to fall. Heavy rains followed later in the day.

But as the first band of the day tuned up behind him, festival co-producer Paul Benjamin told the several thousand die-hard music lovers already gathered in Harbor Park on Sunday morning that the rain was just to wake everyone up. He then promised more blues in Rockland for years to come.

“This is our 17th year, and we’ve got another 17 years,” Benjamin told the cheering crowd. “We are not going anywhere as long as you guys continue to support us.”

Benjamin can likely count Carol LaBree-Mayo and Dale Mayo of Orrington, along with their two sons, Shane and Michael, among his avid supporters.

Standing in front of one of the many food vendors, LaBree-Mayo said she has attended nearly every festival since it began in 1994. In fact, both 13-year-old Shane and 10-year-old Michael have been coming since they were infants.

“We’ve been coming almost every year. I love it,” said La-Bree-Mayo, a blues lover. “I look forward to it every summer.”

The 2010 North Atlantic Blues Festival line-up featured 11 national artists as well as roughly two dozen other individuals and bands who performed between sets or during the traditional Saturday night “club crawl.” That is when restaurants, bars and other establishments throughout downtown Rockland host free concerts.

The daytime performances were anchored by two Grammy Award-winning artists: James Cotton on Saturday and Keb’ Mo’ on Sunday evening.

The other artists and bands that performed on the main stage Saturday and Sunday included: Preston Shannon, Biscuit Miller, John Nemeth, Bryan Lee, Johnny Rawls, Shakura S’Aida, Moreland & Arbuckle, Michael Burks, Shemekia Copeland.

Artists Lydia Warren and Cole Downing entertained the crowd between sets on both days.

Now in its 17th year, the blues festival has grown into one of the biggest annual events for this midcoast city. While coastal Maine may seem an unlikely place for a successful blues festival, the event has attracted enough big-name blues talent to earn an honorary place on the Mississippi Blues Trail.

Rockland is the seventh city outside of Mississippi to earn a “marker” on the Mississippi Blues Trail, a “museum without walls” that traces the history of the blues in the southern state. Rockland was chosen for a marker as acknowledgment of “both the history of the blues in Maine and the idea that blues music now stretches to every region of the United States,” according to a press release on the Thursday ceremony.

Among the thousands who attended this weekend’s festival were Stetson Pierce and Donna Cantone, two friends from Augusta.

Pierce, who’s a blues lover, estimated this was his 12th year attending the North Atlantic Blues Festival — a claim supported by the souvenir tank top he was wearing from the 1998 show. Pierce has been to other blues festivals, but he prefers Rockland’s.

“I think this is the best festival I have ever been to,” he said, adding that the people and the music make it so.

Cantone, meanwhile, was thoroughly enjoying her first North Atlantic Blues Festival.

“I think it’s just fantastic,” Cantone said. “I can’t get over the crowd. I think the atmosphere is wonderful and the people are so friendly.”