The Riverhead Rocks Triathlon and Cardboard Boat Race will be held the same weekend this summer.

Two popular Riverhead events will be held on the same weekend this summer, bringing family fun and a surge of business to downtown Riverhead.

Riverhead’s 4th annual Cardboard Boat Race and the Riverhead Rocks Triathlon, going on its second year, will be combined into one weekend of fun June 29-30.

“We always had the boat race on that [last] Sunday [in June], but because the triathlon depends on the way the tides are, it worked out that the tides will be perfect for the way they need to be for that Sunday,” said Ray Pickersgill, president of the Riverhead Business Improvement District.

The boat race will be June 29 and the triathlon June 30.

Last year’s boat race had close to 100 participants, and brought more than 2,500 people to Riverhead, Mr. Pickersgill said. “It’s amazing people come from all over the island to come and participate in this.”

The event is an opportunity to bring families together.

“Last year I had one mother say to me, ‘You know my son and daughter fight all year long, but the two months before the race they are as thick as thieves building their boat,’ ” Mr. Pickersgill said.

The inaugural Riverhead Rocks Triathlon also drew quite the crowd last year, with more than 450 participants. This year more than 1,000 participants are expected to race, Mr. Pickersgill said.

Last year “the hotels were all booked solid,” Mr. Pickersgill said. “All the restaurants were packed with the people buying dinner and lunch.”

Booths will be set up for local restaurants to sell food during the triathlon and for non-profit organizations to fundraise, Mr. Pickersgill said.

In an effort to promote downtown Riverhead to potential business owners, the district will also open “pop-up stores,” in the empty storefronts on Main Street. With the permission of the landlords, “the empty buildings get transformed for the day and become businesses,” Mr. Pickersgill said.  “So that they can see what it’s like on Main Street, and maybe they will decide to come back.”

Depending on the landlords’ permission, they may be able to open the “pop-up” stores for both events.

“It’s just a great, great family day,” Mr. Pickersgill said.

Last year the Cardboard Boat Race won the Verizon Fios “Best Community Event on Long Island” award, and the Riverhead Rocks Triathlon won its “Best New Event” category.

For information about the either event visit www.riverheadbid.com. For further information on Riverhead Rocks Triathlon visit www.riverheadrocks.com.

cmiller@timesreview.com