All our shoes and boots have plantation crepe soles. Plantation crepe, though more expensive than synthetic soling material, has excellent ethical credentials being sustainably produced and ecologically biodegradeable. It is also an extremely comfortable choice, molding itself to the wearer's natural foot shape. However, some situations require soles where more grip is important (such as on board boats or hiking in hilly districts) so we also offer an additional Vibram sole. Vibram is extremely durable and provides excellent grip.