From: US Department of Transportation, US Coast Guard Navigation Rules - International and Inland as updated through March 15, 2002: INLAND Sound and Light Signals RULE 34 Maneuvering and Warning Signals (a) When power-driven vessels are in sight of one another and meeting or crossing at a distance within half a mile of each other, each vessel underway, when maneuvering as authorized or required by these rules: (i)shall indicate that maneuver by the following signals on her whistle: one short blast to mean "I intend to leave you on my port side"; two short blasts to mean "I intend to leave you on my starboard side"; and three short blasts to mean "I am operating astern propulsion". (ii) upon hearing the one or two blast signal of the other shall, if in agreement, sound the same whistle signal and take the steps necessary to effect a safe passing. If, however, from any cause, the vessel doubts the safety of the proposed maneuver, she shall sound the danger signal specified in paragraph (d) of this Rule and each vessel shall take appropriate precautionary action until a safe passing agreement is made. (b) A vessel may supplement the whistle signals prescribed in paragraph (a) of this Rule by light signals: (GO TO THE ACTUAL DOCUMENT FOR THIS INFORMATION) (c)When in sight of one another: (i) a power-driven vessel intending to overtake another power- driven vessel shall indicate her intention by the following signals on her whistle: -- one short blast to mean "I intend to overtake you on your starboard side"; -- two short blasts to mean "I intend to overtake you on your port side". (ii) the power-driven vessel about to be overtaken shall, if in agreement, sound a similar sound signal. If in doubt, she shall sound the danger signal prescribed in paragraph (d). (d) 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 to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least five short and rapid blasts on the whistle. (e) Covers vessels nearing a bend or an area of a channel or fairway where other vessels may be obscured by an intervening obstruction. (f) Covers vessels with more than one whistle. (g) Covers vessel is leaving a dock or berth. (h) Covers vessels using radiotelephone for communication. ---- END OF QUOTE ---- International signals are considerably less wordy but mean the same thing. Those whistle signals simply state that one short blast means the signaling boat is altering course to starboard (port-to-port meeting or overtake on the starboard side of the vessel to be passed). Two short blasts indicates a proposed starboard-to-starboard meeting or a pass on the port side of the vessel to be passed. I can also provide a complete text in a private message. * * * * * * * * * * * * * ** D C "Mac" Macdonald ** * Grand Lake & OKC - OK * ** AGLCA (#217) & USPS ** ** USAF & FAA, Retired ** ** Amateur Radio K2GKK ** * * * * * * * * * * * * *