I was reading the latest RA transcript and noticed a request for swimming animations. As Rosie stated, there are already several swim spots set up in CDS. I placed these swim rezzers a while back, replacing the older ones we had (with Delia's blessing) because these new ones allow you to swim off-sim.
Here are the locations (there is a sign at each spot, too):
http://maps.secondlife.com/secondlife/L ... s/17/88/22
http://maps.secondlife.com/secondlife/L ... 199/249/21
http://maps.secondlife.com/secondlife/C ... 250/242/21
http://maps.secondlife.com/secondlife/A ... 212/249/22
I believe that is all of them (it's been a while since I placed them). If more are needed, feel free to send me a request.