Whilst no swimming cap will keep your hair 100% dry they will offer you some protection. The reason why no swimming cap is able to do this is because water creeps up whilst your head is below the water line. The rubber caps do offer more protection & are a closer fit They also have a inner seal which helps to repel the water. The fabric swim turbans are designed to be splashproof & are ideal for gentle swimmers, aqua aerobic classes etc. They are usually made from a high quality polyester then have a thin splashproof lining inside (a bit like a shower cap).