As standard, we fit natural plantation crepe to our shoes and boots. Plantation crepe is a natural material, biologically degradeable and sustainably produced. It is more expensive than synthetic soling material but its environmental credentials and the superior comfort it provides, we think, make it an ethical choice. However, whilst hard wearing, it is not non-slip. Under normal circumstances, this will not matter but, if you walk frequently on surfaces where more grip is necessary, we strongly recommend having the additional vibram sole. This is an especial advantage for footwear that will be worn onboard boats or if you hike on rough terrain.