This seaweed has special features that make it able to cope with the daily tides. It has "air bladders"- bubbles of air in its fronds - that hold the plant upright in the water when the tide is in. This helps the seaweed to get as much sunlight as possible to help it grow. If you touched this seaweed it would feel a bit slimy and leathery. The toughness of the fronds and their slimy coating help them not to dry out when the tide is out.