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 MarksRegion A Region A comprises … [Read more...]