What size water polo ball should i buy?

Please use the info below as a guide:

Size 1 - Novelty Ball, Under 6s Boys & Girls

Size 2 - Under 10s Boys & Under 12s Girls

Size 3 - Under 12s Boys & Under 14s Girls

Size 4 - Under 14s Boys & International Women

Size 5 - Senior Boys & International Men

What is the difference between a men's water polo suit and a normal swim suit?

A water polo suit is fully lined front and back where as a swim suit is only front lined