I do aqua fit and we do the crunches with the noodle, by laying out straight on the noodle (it's under our armpits) and then lifting ourselves to a sitting position.
Another one we do is, laying on the noodle as before, bringing our knees up to our chest, then kicking them out straight to one side, then bring your knees up to your chest again and kick out to the other side. It works the sides of your stomach.
If you have foam weights (or I guess you could do it with a noodle), lay flat out on your stomach and push the weights/noodle to the bottom of the pool - a bit like push ups.
You can also do this one..... Stand straight up, slowly bring your knees up (it should look as if you are sitting in a straight backed chair), then slowly lower your legs - feet should be together throughout - this exercise needs to be really controlled and slow - you can use a noode behind you, to help with balance.
Another one that is similar tothe previous one, same movement - but.... Do it with your legs apart and straight (it should look like you are sitting in a straight backed chair, with your legs apart and straight). This one takes a lot of control.
" Success is what you make it, there's no better time to make a change than the present."
"Wherever you go, no matter what the weather, always bring your own sunshine. "