Timing is Key

Going down the west coast we’ll pass several ports guarded by river bars: Westport, Astoria, Tillamook, Newport all have river bars that must be timed well for safe passage.  If the tidal current over the bar is ebbing (flowing out to sea) it counters the prevailing winds and ocean swell that approach from the west and creates steep dangerous waves at the entrance.  The trick is to time your entrance for a flood tide so the current is flowing in the same direction as the wind and swell.  A smooth entrance makes a happy crew.

How to affect that timing? With tide tables!  Best case, we don’t stop at any ports along the way and blow down the coast in blue bird weather, but if the weather turns or problems arise that dictate stopping, it’s nice to be able to time  our departure to optimize our opportunities to stop along the way.  A geek does that with spreadsheets that list distances and travel times.  He annotates it with tidal information and color codes port arrivals according to suitability.  This allows us to choose the optimal departure time.

The attached screen shot shows a sample of the sheet.  Several colored columns were created, each with a different departure time, from which a 4am departure from Port Townsend was selected.