The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) is a non-profit organization founded in 1957 to collect and provide nautical expertise and advice. • Lateral marks indicate the edges of a channel. • Cardinal marks indicate the direction of safe water at a dangerous spot. • Safe water marks indicate the deep water and open end of a channel. • Special marks indicate administrative areas, such as speed restrictions or water skiing areas. • Isolated danger marks indicate a hazard to shipping. Lateral Marks Region A Region A comprises … [Read more...]