Inland waters: two power-driven vessels meeting within half a mile. The other one sounds one short blast. What does she mean?
"I intend to leave you on my port side"
Inland Navigation Rules 34(a)(i)-(ii) (33 CFR 83.34)
Inland waters, meeting within half a mile: she sounds two short blasts. What does she mean?
"I intend to leave you on my starboard side"
Inland Navigation Rules 34(a)(i)(2) (33 CFR 83.34)
A power-driven vessel in sight of you sounds three short blasts. What does it mean?
"I am operating astern propulsion" (backing)
Inland Navigation Rules 34(a)(i)(3) (33 CFR 83.34)
Approaching each other, a vessel sounds five short, rapid blasts. What does it mean?
Danger or doubt: she does not understand your intentions or thinks you are not doing enough to avoid collision
Inland Navigation Rules 34(d) (33 CFR 83.34)
Inland waters, in sight of each other: a power-driven vessel coming up behind you sounds one short blast. What does she mean?
"I intend to overtake you on your starboard side"
Inland Navigation Rules 34(c) (33 CFR 83.34)
Rounding a blind bend in a channel, a vessel sounds one prolonged blast. Why?
To warn vessels that may be hidden around the bend; any vessel there answers with one prolonged blast
Inland Navigation Rules 32(c) and 34(e) (33 CFR 83.32, 83.34)
Inland waters: a power-driven vessel backing out of her berth sounds one prolonged blast. Why?
The Inland Rules require one prolonged blast when leaving a dock or berth
Inland Navigation Rules 34(g) (33 CFR 83.34)
In thick fog you hear one prolonged blast about every two minutes. What is out there?
A power-driven vessel making way through the water
Inland Navigation Rules 35(a) (33 CFR 83.35)
In fog you hear two prolonged blasts, about 2 seconds apart, every two minutes. What is it?
A power-driven vessel underway but stopped, not making way
Inland Navigation Rules 35(b) (33 CFR 83.35)
In fog: one prolonged blast followed by two short blasts, every two minutes. Which of these could it be?
A sailing vessel, a vessel fishing, towing or pushing, not under command, or restricted in her ability to maneuver
Inland Navigation Rules 35(c) (33 CFR 83.35)
In fog you hear a bell rung rapidly for about 5 seconds, once a minute. What is it?
A vessel at anchor
Inland Navigation Rules 35(g)-(h) (33 CFR 83.35)
In fog, right after a towing vessel's signal, you hear one prolonged and three short blasts. What is it?
The last vessel of a tow, if manned
Inland Navigation Rules 35(e) (33 CFR 83.35)
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