Hazard to navigation is a term used to describe any obstacle or danger that can impede the safe passage of a vessel. The crossword solutions for this term are ICE (3 letters), HAZE (4 letters), BERG (4 letters), SHOAL (5 letters), FOG (3 letters), and EDDY (4 letters). ICE is a solid form of water that can form on the surface of bodies of water, making it difficult for vessels to pass through. HAZE is a type of air pollution that reduces visibility, making it difficult to navigate. A berg is a large mass of floating ICE, which can be dangerous for vessels to pass by. A SHOAL is a shallow area of water, which can cause vessels to run aground. FOG is a cloud of water droplets that can reduce visibility, making it difficult to navigate. An EDDY is a swirling current of water that can cause vessels to drift off course.