Nautical danger can refer to a variety of hazards that sailors may encounter while out at sea. TEMPEST, a seven letter word, is a violent storm with strong winds and heavy rain. REEF, a four letter word, is an underwater formation of rocks or coral that can be hazardous to ships. Sandreef, an eight letter word, is a shallow REEF made of sand that can be difficult to spot and can cause a ship to run aground. All three of these terms are associated with nautical danger.