I’m going to take the unpopular opinion here and say I think he’s in the water due to self-harm.
Just because someone is making future plans, as we know on this forum, does not mean they are not depressed or masking. The reason I asked upthread if he and his friends had been drinking is because I know how the highs and lows of drinking work. His dad is reassured because Caleb was texting him during the evening talking about fishing lures, but that could be the “high” of alcohol (if they were drinking). How many of you have gone out drinking and made “drunk plans” never to do the things you all discussed the night you were drunk? Alcohol is fun…at first. But the withdrawal from alcohol after the evening is over, especially if you’re already depressed (I’m not saying Caleb was), is terrible. It’s a depressant and it typically leaves you feeling worse than before you drank. It feels like the world and all your life decisions come crashing down on you. It’s very heavy.
I know there is a lot of assumption on my part that he and his friends were drinking, but I’m making that assumption based on a group of college kids that are of legal age to drink, living in an off-campus apartment in a college town. Not to mention they were up and outside extremely late at night/early in the morning. What else would they be doing? Studying? lol
I don’t think he was hit by a car (there would be some evidence) and I definitely don’t think he was abducted; what would the motive be? To me, the only explanation is, he walked off on his own accord.