five
a pie
None. At least, none in the main World Cup as opposed to the age-restricted ones (Under-21, etc).
If one is looking for rowing machines under $300 and with a compact design which can be easily stored, there are few cheap rowing machine on the market. These include: Stamina 1215, Stamina Air Rower, Fitness Rower.
6 championships
The New York Yankees won their first of five consecutive world championships under manager Casey Stengel by beating the Brooklyn Dodgers in five games.
In 1961 under the name modern gymnastics, and in 1963 the first Rhythmic World Championships took place.
The Yankees beat the Brooklyn Dodgers in five games to win the first of five consecutive world championships under manager Casey Stengel.
Maryland won three ACC championships (1974, 1975, 1976) under head coach Jerry Claiborne.
5
The University of Tennessee under pat Summitt
Depending on what country you are in and which organisation you dance for, I believe the youngest age you can be to compete in major championships is Under 7, and I believe you have to be 9 or 10 to compete in Worlds.
Both are really hard, it just depends in what sense you mean. Flat water is extremely technical in terms of the dynamics of the stroke, and the 2k race distance is a world of pain. In surf rowing, the stroke is not as technical, but you are bouncing over waves, meaning you regularly become airborne and are trying to keep rowing while the boat just drops out from under you. The boat is also far heavier. As to which one is more difficult, it largely depends on skills and experience. Having done both competitively, I would say that personally I find surf rowing more difficult.