Judging by the spider cracks and displaced pop-rivet, the boat "took a hit" right at the rivet.
If you suspect a leak, remove the trim, take a hacksaw blade (or metal-cutting saber saw blade) and separate the hull there. Epoxy the deck and hull back together. Use clamps on paint stir-sticks until cured. Reattach trim with aluminum pop-rivets. If 1/4" rivet-heads appear above the trim, use 1/8" grip.
I doubt caulk will work long-term, and any later painting may not adhere properly.
No reason to if the deck/hull seam is sealed. Caulk will not work on popped seams, and dirt/sand/grime/etc... will stick to it. L&VW has the correct repair method, we'll add that thickened epoxy is best because of its gap filling qualities. We use a syringe to inject it into the seam and lightly clamp while it cures.Too much clamp pressure will squeeze epoxy right back out of the joint.
On the flip side, as a restorer, When we get boats with a grimy strip of caulk on them we know where one of our repair areas will be