It’s been an interesting 72 hours for SpaceX CEO Elon Musk. He went from having a team create a min-sub from rocket parts to testing it out in an LA pool to then traveling to Thailand. All done in order to try and help the group of Thai boys and their coach escape from a cave.

Musk shared the last leg of his efforts to help the trapped soccer team and their coach on his Instagram account Monday. The video (above) shows the waist-high waters and unique formation of the Tham Luang Nang Non cave, which complicated the rescue of the group who had been inside since June 23.

Rescue divers began retrieving the children on Sunday, and so far, eight have been rescued with plans to extract four more boys and their coach on Monday.

“Just returned from Cave 3,” Musk writes in a tweet posted Monday afternoon. “Mini-sub is ready if needed. It is made of rocket parts & named Wild Boar after kids’ soccer team. Leaving here in case it may be useful in the future. Thailand is so beautiful.”

Musk first tweeted about helping with rescue efforts on July 4. Musk suggested the idea of drilling a hole or using an inflatable nylon tube to act like a “bouncy castle.” He eventually sent SpaceX engineers to help with the rescue, but also had a team creating a mini-sub prototype in eight hours based on the feedback from his engineers at the cave.

A group of 12 boys and their coach were found on July 2 by rescue divers in a cave after being trapped for 10 days.

Preparations are underway to save the final members of the group, according to the BBC on Tuesday. The health of the four boys and their coach have been said to be good, while the rescued eight others are recovering at a hospital in the nearby city of Chiang Rai.

The rescue effort to save the group from the cave consisted of more than 90 people, with more than half being foreign help. Helicopters and drones were also used in order to find a possible extraction point for the group.

Photos via Thai Navy SEALS, Elon Musk