Yeah, he's very lucky. Given the massive blood loss it sounds like one of the bone fragments cut into his femoral artery.
Sadly, this might delay the release of the much anticipated "Poseidon Rex".
I'll go ahead and start a rumor that the barge was partially submerged because Christopher Judge had slammed into it earlier on a wave-runner, accidentally ripping open the steel hull with his elbow, after which he swam to shore, popped open a Corona and addressed the worried crew, saying "I am uninjured. I believe the design of the barge to be defective."