Premise: "Small child wearing a yellow life jacket walks in the sand with their boogieboard on their head."
Hypothesis: "A boy prepares to ride his boogieboard in the ocean."
Do we know that the hypothesis entailed by the premise? Let's be accurate as possible and think first.
The child might not be a boy. Not everyone who carries a board prepares to ride it. There might not be an ocean. Final answer: it is not possible to tell.