Originally Posted by Tom Spohn
You won't find current
data for the Swinomish Channel. Here is what the locals do:
Use the La Conner tide readings (Seattle + 30 minutes)
Slack water occurs 2 1/2 to 4 hours after either high or low tide
Current flows north 2 1/2 to 4 hours before high tide to 2 1/2 to 4 hours after high tide
Current flows south 2 1/2 to 4 hours before low tide to 2 1/2 to 4 hours after low tide
I apologize for being dense but I am not entirely clear on the above. As an example, if high tide for La Conner occurs at 3PM, the way I read it the current
should be flowing north from approximately noon until 6PM, then slack at approximately 6PM, then flow south from 6PM until about midnight. This assumes 3 hour intervals instead of the 2.5-4 hours in the rule
above, but you get my point. Does this sound about right?
I will be moving our boat up the Swinomish from La Conner this Friday afternoon and am curious about what the current will be doing.