My understanding from the people I know who taught military recruits, as well as other sources, is that there is much higher percentage of african-americans who don't know how to swim. Not being able to swim is kind of a big deal for scuba diving.
How many Americans can't swim?
"The Memphis study broke the data down demographically. White children were the most likely to self-report (or have their parents report) strong swimming skills, with 58 percent of those between the ages of 4 and 18 claiming the ability to traverse more than a pool length. Hawaiians and Pacific Islanders came in a close second at 55 percent. Forty-two percent of Hispanic and Latino children are strong swimmers. Asian-American and Native American children came in at 34 percent and 32 percent, respectively. African-Americans reported the fewest strong swimmers at 31 percent. Accident rates largely conform to these data. Black children between 5 and 14 years old are more than three times as likely to drown as their white peers. The six children who died in Louisiana were African-American."
