Ive previously owned a pair of Speedo Zip Walkers in a size 5 (they ran a whole size bigger that year) and they lasted through two summers. They seem to hold up well. Ive used them for water aerobics 3 times a week, rinsing thoroughly after each use.
These are so comfortable that I ended up purchasing 2 pairs in navy because that color seems to be discontinued. The pictures for the navy don't do it justice. They are gorgeous and much darker than pictured. They pair well with my Sporti unitard also in navy (unitards are so much better for water aerobics, no more overstretched, unflattering tankinis for me).
Im usually a size 6.5 and purchased the 6 and still have plenty of toe room. These also seem to have more cushioning than the previous version and a much better zipper.