The best choice you can make for a foot/ankle combination suitable for scuba diving and walking is the Adaptive Sports Ankle w/Otto Bock Aqualine foot. The Adaptive Sports Ankle is designed for that very use, made from Grade 5 Titanium so it will never rust and designed to never break. The Otto Bock Aqualine foot is made to be water proof (no foot shell, but solid rubber w/titanium male pylon connection. The combo is truly awesome.
The Adaptive Sports Ankle is designed to plantar 50 degree (human ankle natural range of motion) by pressing a button on the ankle front side or pressing/pulling a lever/ring on the ankle rear side. Internal torsion springs rotate the ankle, so you can manipulate the foot "hands free". Same actions release the ankle for a return to a neutral position for walking. The Rampro and the Freedom Innovations products are for SWIM ONLY, not for walking or they will break. check the Adaptive Sports Ankle website for more info.