The Houston Rockets player turned 26 on Wednesday and celebrated with a cruise Tuesday night

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James Harden‘s lavish 26th birthday bash was a family affair for the Kardashians and Jenners.

Kourtney Kardashian, Kim Kardashian West, Kanye West, Kendall Jenner, Kylie Jenner and Tyga partied along with Khloé Kardashian and her basketball player boyfriend on a the yacht FantaSea in Marina del Rey, California, on Tuesday night.

Khloé, 31, began dating Harden, who plays for the Houston Rockets, in early July, when they celebrated Independence Day clubbing in Las Vegas. The reality star was last linked to rapper French Montana after splitting from husband Lamar Odom, also a former NBA pro, in 2013.

The cruise comes two weeks after she jetted off to Texas with Harden following her altercation with Odom, 35, outside her Los Angeles gym.

Kendall, 19, posted Instagrams of herself rocking a sailor’s cap in a photo booth. Sister Kylie, 18, also took fans inside the festivities on social media, posting an Instagram of the group getting silly and Snapchats throughout the evening.

Kourtney, 36, and Kim, 34, also posted Instagrams and Tweets from the booth.

The guests, dressed in all white, took a party bus to the celebration. Kris Jenner and her boyfriend Corey Gamble, Amber Rose and basketball player Baron Davis were also among the about 200 revelers, a source says.

Aboard the boat, the celebrities sipped champagne, hit the dance floor beneath a canopy of twinkle lights and cheered during a dazzling fireworks show at midnight.

“Guests seemed to have a great time. They all sang ‘Happy Birthday,’ ” the source tells PEOPLE. “The fireworks show was amazing. It went on for a while and lit up the whole sky. Everyone was very impressed. Khloé had organized everything with the help of [party planner] Sharon Sacks. James seemed very happy.”

Keeping Up with the Kardashians returns Sept. 20 at 8 p.m. ET on E!