We almost drowned when we went out boating, but I got a watermelon to keep me floating.
Watermelon Saves the Day
Explanation
Explain Bear
Listen up, buttercup. This joke is all about wordplay, see? The joke teller almost "drowned" (meaning sinking in water and dying), but because they had a watermelon, it kept them "floating" (staying on top of the water). It's a play on words, because a watermelon is something that floats! And you, my friend, probably sink in a pool.