There were no cops waiting to arrest him at the port. In fact, unless he self-reported to his probation officer that he committed a violation, I'm not sure how the authorities would even be aware of this excursion. Once he got off the ship he would have been home-free.
But for some reason if he was worried about violating probation and wanted to disappear, he could have just walked off the ship normally, got in his car and driven away. No one would have been the wiser. Eventually a court may have put out a warrant for his arrest. But people walk around with active warrants every day. And if he left the state it's unlikely anyone would even pursue him for some relatively low level offenses.
Instead, now Kevin's name and face are plastered across the media nationwide. The authorities know about his excursion and he's got the cops, the feds and everyone else out looking for him. I live halfway across the country and I would probably recognize him now if I saw him on the street.
I respect everyone's opinion, but I just can't see how any of this supposed cloak-and-dagger stuff makes sense. And from what little we know of him I don't believe he has the resources, connections, or guile that he would need to successfully pull off a ruse of this sort.
IMO, the simplest explanation is the most likely: at some point during the night or in the early morning hours he went overboard and likely drowned.