Not a problem and not unusual. The tides for the 5th are in between the full and new moon. Look at the full moon tides, same area, Port Townsend:
12th at 8:56PM -3.0 Low
13th at 5:12AM 9.4 High = + 12.4
13th at 9:17AM 6.9 Low = - 2.5
13th at 2:31PM 9.3 High = + 2.4
13th at 9:42PM -3.2 Low = - 12.5
These are pretty common tides here. 6,8,10 ft variations and sometimes down to 2 or 4. Makes some approaches time sensitive. There are places on the coast where 15 to 20 foot tides are the norm. And there are places where tidal changes cause currents that run in the 5 - 8 knot bracket. There are some that are higher than that. (Skookumchuk Rapids up on the BC coast for example). Juan de Fuca Strait often has 3 - 5 knot current running at max flow times.
Hey, it's good you are doing your home work. Don't let the tide changes get to you. What you want to be aware of is the "tide rips" where opposing tides come together around a point of land. Marrowstone Point, or Point Wilson, both close to Port Townsend, are good examples. Cattle Point, which is one of the main entrances to the San Juan Islands from the south off the Strait of Juan, is another fine example of a rip to watch for.
All of these are negotiable, by watching the current direction, the time, and the rips. All of the rips are stronger in some areas than others, and being fluid, changes occur during the flow change, so keeping a good eye out, some local knowledge, and good boat handling skills will get you through. Patience and planning are both essential.
Harvey
SleepyC:moon
