New hot tub boats are cruising through Boston Harbor: "I'm excited to come back."

There's a new kind of cruise on the Boston Harbor. It's in a hot tub.

Boston Hot Tub Boats has officially opened and is setting sail out of Atlantis Marina in Winthrop, Massachusetts. The custom floating hot tub can seat up to six people. It moves at a cool three miles per hour through the calm waters north of Logan Airport.

Marie Bocquet brought the concept to the area after first seeing it on a trip to Copenhagen, Denmark. There are changing tents, waterproof phone cases, and Bluetooth speakers for the "bring your own beverage" experience. The company even sets your preferred water temperature before you arrive.

"It's picking up well for the moment," Bocquet told CBS News Boston. "I sort of kept this idea in mind, and when we moved to Boston, I thought there was an opportunity. We have the water, the ocean. There was room for fun."

The water in the hot tub is warmed by firewood, and the boat is powered by an electric motor. The company said the hot tub is completely drained, cleaned and refilled with fresh water in between sessions.

Hot tub boat rentals start at $493 for a two-hour ride out of Atlantis Marina. The company opened two weeks ago and has been busy since. Caroline Barry took a two-hour cruise with her mother and friends.

"I had seen a friend in Chicago do it, and then I saw it got brought to Boston, so I'm all about finding new, unique activities in Boston," Barry said.

"I'm excited to come back during winter to enjoy it," said Barry's friend Steph Crawford. "Do it year round."