The Cressi Ultra Stretch Socks 2mm socks are the perfect item to have when snorkeling or spearfishing. 

They are a neoprene sock that are designed to be worn inside fins to prevent blisters or chaffing as well as giving warmth and protection when walking around when your fins are off. 

The grippy bottoms will prevent you from slipping when climbing down the rocks to get in to the water.