Contract Altro Marine 20 Cascade IPT20809 Speckled Effect Non Slip Commercial Vinyl Flooring. Altro Marine 20 has a dimpled surface thats specially designed for bare feet where you need Class C and the risk of a slip is very high. It provides excellent slip resistance and its hardwearing construction makes it resistant to most chemicals and indentation. It is easy to maintain, so it will keep looking good and performing well.