I feel it's more culture than race. Seems income is a big factor. Most likely to affect marginalized communities. I see it a lot in the Philippines also. Maybe it's less access to swimming lessons and pools to practice in.
Muscle/fat distribution and how this influences ability to float is a big factor in drowning rates among populations without access to swim lessons. Statistically there are significant differences in that distribution based on race, age, and gender.
You ever swim with clothes on? Like a pair of jeans? It's way harder, way more energy gets expended to stay above water. Even with knowing how to swim, having a reduced ability to float can be incredibly dangerous.
