🔍 Key Concepts

• Inland Navigation Rules and U.S. lock regulations for sound signals • Difference between long blast and short blast meanings on inland waters • How signals change when entering different chambers or directions (riverward vs landward)

💭 Think About

• Think about what kind of signal a lockmaster would use to clearly distinguish permission for the riverward chamber from other routine or danger signals. • Ask yourself which of these signals is least likely to be confused with common maneuvering signals like port/starboard alterations or backing. • Consider how many blasts are typically used for special instructions or permissions versus standard meeting/crossing intentions.

✅ Before You Answer

• Verify how many blasts are specified in Corps of Engineers / lock regulations for entering each chamber direction. • Check that the signal you choose would not be easily mistaken for a standard danger signal or basic maneuvering signal used between vessels. • Confirm that the pattern (number and length of blasts) is unique enough to clearly indicate permission to enter the riverward chamber rather than a general movement.