There are different rules and major differences regarding
the size, weight and pressure of the balls used during official
Federation Internationale de Natation Amateur (FINA) play.
Official FINA men's water polo balls have a larger circumference,
which means they are larger around than women's balls. According
to FINA rules, men's balls must be between 0.68 and 0.71 meters
in circumference or between 26.8 and 28 inches around. Women's
balls are smaller, and FINA rules state that they should be
between 0.65 and 0.67 meters in circumference, which is between
25.6 and 26.4 inches around.
Men's water polo balls use more pressure in the balls as
well, meaning the balls are filled with more air, partially
due to the size of the ball. According to FINA, men's balls
must be between 13 and 14 lbs. per square inch of pressure.
Women's balls under FINA rules must be between 12 and 13 lbs.
per square inch of pressure.
Surprisingly, there are no differences in the rules regarding
the weight of women's and men's water polo balls. FINA rules
state that all water polo balls must weigh between 400 and
450 g. That translates to a range between 14.1 and 15.9 oz.
in weight. Men's and women's water polo balls are not made
specifically to weigh differently, but they may feel that
way simply because of the circumference and the air pressure.
FINA rules regarding ball sizes apply to all international
and adult levels of water polo, which include any age groups
over the age of 14. There are some differences in ball sizes
for younger ages of boys' and girls' water polo as well. According
to USA Water Polo, both genders from ages 5 to 9 and ages
10 and under use the same size ball. In the 12 and under age
group, boys' water polo moves to a larger size ball, known
as Intermediate Size 3, while girls still play with the 10
and under ball called Junior Size 2. At the 14 and under age
group, girls move to the Intermediate Size 3, while boys advance
to the Compact Size 4, which is the same size used for official
FINA play for older women's games.