Five short blasts from another vessel's horn typically signal danger or an uncertain maneuver. It serves as a warning to nearby vessels that the signaling vessel is unsure of the other vessel's intentions or is indicating a potential collision risk. In maritime communication, this signal emphasizes the need for caution and awareness in navigating close quarters.
They are indicating dangerous
When vessels in sight of one another are approaching each other and from any cause either vessel fails to understand the intentions or actions of the other, or is in doubt whether sufficient action is being taken by the other to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least five short and rapid blasts on the whistle
From the USCG Navigational Rules of the Road (International and Inland.)Rule 34Maneuvering and Warning Signals(d) When vessels in sight of one another are approaching each other and from any cause one fails to understand the intentions or actions of another, or is in doubt whether sufficient action is being taken by the other to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least 5 short and rapid blasts of the ships whistle.
they are indicating a dangerous situation exist
No, boats, barges, floating platforms, etc. are also vessels. A vessel is basically anything that floats and can be moved, either by own means or by being towed by another vessel.
vessels operator
It depends on what they are being used for. It is not always or even mostly true.
When vessels in sight of one another are approaching each other and from any cause either vessel fails to understand the intentions or actions of the other, or is in doubt whether sufficient action is being taken by the other to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least five short and rapid blasts on the whistle
Sailboard
A vessel's lifeboat.
Canoes and kayaks.
Depends on the situation. If you signaled in advance and had room to pull out without interrupting the flow of traffic then the other driver is at fault. However if you did not signal and attempted to pull out without being aware of on coming traffic you are at fault.