In Phuket, Thailand we generally see hard growth as barnacles and mussels. These organisms frequently attach to metals, such as your prop and shaft and will significantly impact your boats performance.  Anti-fouling Paint is designed to prevent barnacles but long periods without cleanings can result in barnacles attaching to the hull as well. Consistent maintenance helps reduce hard growth. Soft growth is the layers of marine slime and algae that clings to your boat’s hull and slows your boat down. Soft growth start to bild up at the waterline quickly.