Like I said your legal, 100%. But the CO can charge you. Don't argue with me about it. He has the legal right. What are you going to do if he says he's writing you a 250 ticket? Tell him you refuse to except it?
As for a CO not checking you out for have a gun uncased in a boat out of season, pretty sure he would check you and if he didn't he probably isn't doing his job because that would not look so good.
But hey your legal to carry the rifle. But in all honesty some on here sound like their attempting to almost challenge a CO. That almost always goes bad. I preferr to carefully choose my battles.