The density of the bones in the Negroid race, along with lack of sub-cutaneous body fat makes it very difficult for blacks to float. On the other hand, women have more sub-cutaneous fat, and the bones are less dense, making them the most likely to float, so more likely to have lack of fear to learn how to. Floating is the first thing a person learning to swim must do to feel comfortable in the water.
I was just reading something - I think it was a rookie football player (black guy) that was talking about growing up. Something to the effect of “I was a lifeguard as a teen. My younger brother and sister were good swimmers too. But they would be in the pool that I would be at and would always pretend to be drowning. You know - black folks can’t swim and all that.”
I worked in Wyoming at one time on the oil rigs. A boss explained why so few black people in Wyoming. “They don’t like the wind.” (I must be part black!)
I could probably float a lot better today (ha ha), but do not have the desire to swim anymore.