Tide times are often listed in 24 hour time.  For times after noon, subtract 1200 from the time to get regular clock time. Ex: 1300 hrs – 1200 = 1:00 pm)

MLLW:  Also, tides are referenced to Mean Lower Low Water, a reference point for depth on many nautical charts. MLLW is the average of the lower of the two low tides in a day, over a 19-year cycle. Minus tides are lower than MLLW.

Adjustments: If you’re right on the coast, subtract an hour from these times. Upriver, highs and lows happen later. For instance, in Knappa, add an hour. In Clatskanie, add 2 hours and 15 minutes.

Also on Facebook and Twitter(US Coast Guard).

Commonly Heard off Astoria

One prolonged blast every two minutes or less: vessel operating in fog.

Five consecutive horn blasts: warning signal that means literally “I do not know your intention.” This generally means another vessel is in the way of a ship in the channel, and is being asked to move before they collide.

Three short blasts: Vessel going in reverse

One long blast followed by three short: signal for the change of pilots. Soon after this signal, you’ll see the pilot launch Arrow II head out to a passing ship, to facilitate the transfer of bar and river pilots.