It means "I am altering my course to starboard"
Toot
toot
A. Three long blast of the ships whistle or general alarm at an interval of three, means a man overboard. This is dismissed by three short whistle blast. B. Three Short blast can also be Rule 34 (Inland and International) "Maneuvering and Warning Signals." Three short blast means "I am operating astern propulsion."
Two short horn blast from a vessel means that she is turning port and one short horn blast that she is turning starboard
Runaway ship
You could 'toot' your horn...
A. Three prolonged blast of the ships whistle or general alarm at an interval of three means a man overboard. This is dismissed by three short whistle blast.B. Three Short blast can also be Rule 34 "Maneuvering and Warning Signals."Three short blast means "I am operating astern propulsion."
"I am about to turn to starboard".
On seagoing vessels in restricted visibility a prolonged blast on the ships whistle means the vessel is making way through the water.
three short blast
A whistle or horn
One short blast of a horn mean while boating may mean a couple of things depending on where you are. Some of the meanings of the short blast include request for drawbridge to open, intention to pass of the left side and intention to change course to starboard among others.