Restricted Visibility ALL0-9ABCDEFGHIJKLMNOPQRSTUVWXYZVisibility restricted by rain, drizzle, fog, etc., during which vessels are required to proceed at a safe speed and to navigate with extreme caution Related content: Rules of the RoadKnowing the rules (the highway code for the water) will keep you safe and confident about what to do when approaching another vessel. Learn the rules & how to interpret them. Approximately 3 hoursIRPCS: International Regulations for Preventing Collisions at SeaSpecial Rules & Regulations« Back to Glossary Index