Most male swimmers struggle with synchronized swimming because of a more limited flexibility and inferior buoyancy than their female counterparts.
Synchronized swimmers are incredibly strong swimmers with high levels of endurance that match or exceed most male swimmers. A female synchronized swimmer has much more difficult training regimen than male water polo players. Some males however can compete at the level of women in the sport.
http://www.youtube.com/watch?v=nDJc8tC5i4g