3 blasts on the horn says you are going astern
A boat is astern propulsion and is in the act of backing up
Three short blasts tell other boaters, “I am operating astern propulsion.” For some vessels, this tells other boaters, “I am backing up.”
One long honk on the horn
three short blast
Three short blasts means you are operating in reverse. One prolonged blast followed by 3 short blasts means boat under tow in redcued visibility conditions.
Passing on your starboard (right) side.
When two boats approach each other, they use horn blasts to signal the other about their intentions when it comes to moving to avoid collision. 5 short blasts indicates that the signaling boat is unsure about what the other boat is doing.
Five short horn blasts from another boat on the water usually means danger. It could mean they have doubt in the message they had received from you, whether they did not hear it or did not understand. It can also be used to signal that the boat driver is confused about who has the right away. It is a signal to alert another vessel that you are unsure of its intentions, or doubt whether you are taking enough action to avoid a collision.
Means it's about to turn to port.
A boat is using astern propulsion and is in the act of backing up.
Six blasts of a ship's horn does not seem to have a meaning. Five blasts will mean that you are possibly too close to another ship.