There are many signals a complete list cam be found in the rules for avoiding collisions at sea
A power-driven vessel under way sounds one prolonged blast not less than every two minutes. However if it is less than 12meters in length it is not required to give any signal.
one prolonged blast
one prolonged blast
When a power-driven vessel is being overtaken by another power-driven vessel, the overtaken vessel is the stand-on vessel. This means the overtaken vessel should maintain its course and speed, while the overtaking vessel is required to take action to avoid a collision. It is the responsibility of the overtaking vessel to ensure safe passage and to maneuver appropriately.
In restricted visibility, a power-driven vessel under way is required to sound one prolonged blast every 2 minutes. This signal is used to indicate the vessel's position and to alert other vessels in the vicinity. The prolonged blast lasts for about four to six seconds.
the power driven vessel needs to give-way for sailing ships.
one prolonged blast
one prolonged blast
one prolonged blast
One prolonged blast
One prolonged blast
one prolonged blast.