I have a lot of ankle issues (I'm working on getting them taken care of), so I'm looking for cardio exercises that are low or completely non-impact (preferred) on the ankles to keep my cardio ability up. Any suggestions?
have you got access to a gym? Intervals on the rowing machine, exercise bike/low bike.
I was advised to avoid swimming when I was recuperating from my ankle injury, ask your physio for advice (mine recommended spin classes).
I can't use my foot right now but I have a water proof boot that I can't swim with and I swim laps everyday after my 4 hour long conditioning! I used to be on sum team so I swim about 60-80 laps every time but I would start with what your comfortable with. Don't set an certain number when you first start just swim until you feel like you can't do it anymore. Swimmings is also the time I think about everything, kinda like in the shower it's great.
go in the pool, but no swimming. instead get a wet vest (makes you stay upright in the deep water) and learn to do aquajogging. it's hard but works like a charm especially for nursing ankles back to full impact. you go from no contact to the floor of the pool (deep water, wet vest) in the first sessions to light contact (waterdepth that allows you to stand on tiptoes, wet vest), to full contact (water you can comfortably stand in).
if not possible - stick to (stationary) bike and perhaps the rower.