http://www.iupuijags.com/sports/2007/12 ... aspx?id=16
Permanent seating + temporary additional seating on the deck means the arena can hold 6,200 fans...think Western Hall (a little bigger, actually) with a swimming pool in the middle.
Here's the description from an article on a competitive swimming website that was listing the top 10 best places for a swim meet in the US:
1. IU Natatorium, Indianapolis, Indiana – The biggest permanent swimming facility in the United States is perhaps home to the bulk of its history in the last 30 years. This pool on the campus of IUPUI is not just A natatorium. It is THE natatorium. All fast racers come to Indy. Since opening to 1982, the pool according to its official website has seen 103 American Records and 15 World Records. It has hosted 13 men’s NCAA Championship meets, 13 women’s NCAA Championship meets, and through an agreement with the NCAA will see several more over the next decade for all divisions. They hosted 8 of the first historic 14 women’s NCAA Championship meets after full inclusion in the 80’s. The history here is just unreal – the pool designed to be a mecca of American swimming has done just that, hosting four Olympic Trials meets out of five between 1984 and 2000.
Full size version here.