Maritime Sound Signals

Front 1

International - I am altering course to starboard

Back 1

1 short blast

Front 2

International - I am alterning course to port

Back 2

2 short blasts

Front 3

International - I am operating astern propulsion

Back 3

3 short blasts

Front 4

International/Inland - Danger/Doubt sound signal

Back 4

5 short blasts

Front 5

International - Sound signal for nearing an obscured bend

Back 5

1 prolonged blast

Front 6

International - Narrow Channel Overtaking: I intend to overtake you on your starboard side

Back 6

2 Prolonged followed by 1 Short blasts

Front 7

International - Narrow Channel Overtaking: I intend to overtake you on your port side

Back 7

2 Prolonged followed by 2 short blasts

Front 8

International - Narrow Channel Overtaken: to respond with a yes (Shall)

Back 8

1 Prolonged, 1 Short, 1 Prolonged, 1 Short blasts

Front 9

International - Narrow Channel Overtaken: to respond with a No (May)

Back 9

5 short blasts

Front 10

International/Inland - A power driven vessel underway, making way restricted visibility

Back 10

1 prolonged blast not more than two minute interval

Front 11

International/Inland - Power driven vessel, underway not making way

Back 11

2 Prolonged blasts

Front 12

International/Inland - all encumbered vessels (NRCFST) underway in restricted visibility, not more than two minute interval

Back 12

1 Prolonged followed by 2 short blasts

Front 13

International/Inland - Manned vessel being towed, underway in restricted visibility not more than two minute interval

Back 13

1 Prolonged followed by 3 short blasts

Front 14

International/Inland - Pilot Vessel underway or at anchor in restricted visibility not more than two minute interval

Back 14

4 short blasts

Front 15

International - vessel 20m to <100m Inland Greater than 12m to <100m shall sound in restricted visibility not underway not more than 1 minute interval

Back 15

Rapid ringing Bell 5 seconds

Front 16

International/Inland greater than or = to 100m shall sound in restricted visibility not underway not more than 1 minute interval

Back 16

5 second Bell forward, then 5 second Gong aft.

Front 17

International/Inland- To give warning of possibility of collision when anchored in restricted visibility

Back 17

1 short, 1 prolonged, 1 short blast

Front 18

International/Inland- to signal a vessel aground in restricted visibility shall sound

Back 18

3 bell strokes before and after 5 seconds ringing of a bell.

Front 19

Inland - Maneuvering/Warning signals (in sight, within 1/2 mile meeting or crossing)

I intend to leave you on my port side

Back 19

1 short blast

Front 20

Inland - Maneuvering/Warning signals (in sight, within 1/2 mile meeting or crossing)

I intend to leave you on my starboard side

Back 20

2 short blasts

Front 21

Inland - Maneuvering/Warning signals (in sight, within 1/2 mile meeting or crossing) Answering vessel SHALL answer with

Back 21

same signal
1 short for port to port
2 short for stb to stb

Front 22

Inland - a vessel when nearing a bend, leaving berth (Shall Sound)

Back 22

1 Prolonged blast

Front 23

Inland - A vessel overtaking another vessel shall sound, I intend to overtake you on your starboard side

Back 23

1 short blast

Front 24

Inland - A vessel overtaking another vessel shall sound, I intend to overtake you on your port side

Back 24

2 short blasts

Front 25

Inland - In an situation where you are being overtaken on your starboard side, your answer sound signal shall be

Back 25

1 short for okay to overtake me on my starboard side

Front 26

Inland - In an situation where you are being overtaken on your port side, your answer sound signal shall be

Back 26

2 short for okay to overtake me on my port side