The Ultra is a lightweight. versatile men’s amphibious shoe for exploring along the shore.The Ultra III Bloom has a honeycomb design made from 5% algaeBLOOM ® foam. letting you explore land and sea with grip. flexibility and full barefoot feeling. Versatile and quick to dry. it’s ideal for sailing and most other water sports. Recommended by top surfer John John Florence for strengthening foot muscles and sensory perception. which are fundamental to injury reduction and surfing with power