Instruct: Classify an Amazon review into positive or negative sentiment.
Query: leave blister on back of foot

I bought these for snorkeling and when I put them on with my fins I started to get a blister on the back of my foot. They are very soft neoprene so they offer limited protection on the foot. also when I took them off to walk on the rocky areas, they do not protect the feet very well so you might be better wearing a heavy sock with fins vs spending the money on these.