Summer is definitely the safest time to make the trip. Getting on to winter a series of lows march across the North Pacific
on a weekly basis. When I say 'low', read storm. The chances are very good you'll get hit by a significant storm at least three times if you leave other than late May through early September.
The typical route
for a sailboat is to head
north from Hawaii
and go around the top of the high at anywhere from 40-60 degrees north depending on its location. Typically it's a close reach out of Hawaii
that will ease to a beam reach as you go around the High. Even in summer, it will be a cool trip as sea water
temps will not be above 60 degrees once you leave the environs of Hawaii. Even in Summer, you can get some nasty weather
. Boats returning from Hawaii after the Single
in Augustna couple of years back got a succession of lows that resulted in one being abandoned. One skipper
, even though very experienced and familiar with his boat, abandoned it largely due to exhaustion with the prospect of many more days of foul weather
that had driven him way south.
Another strategy to use if you have plenty of fuel
and want to go to points further south on the mainland involves powering through the high. You'd sail North staying as hard on the wind
as you can comfortably live with till you enter the high. In the high, there is little wind
so you plot a rhumb line course direct to your destination
till you come out of the high on the other side. Once you get wind which will typically be NW, you then sail on a reach to SF or LA for the final part of the passage
. Might even work for Seattle depending on the location of the high. This takes lots of fuel
as you will have to power for a week or more to get through the high. Know of one guy who made the trip several times lashing a 40 gallon drum in the cockpit
to augment the boats fuel tankage. His last trip had to be abandoned. The wave conditions were pitching the boat about so much the lashed barrel threatened to break loose before he reached the high. He turned around, sailed back to Kona and sold the boat.
Last and not usually possible is to sail under the high. That will usually result in a beat the whole way. A very uncomfortable and wet trip. Shortest distance though probably not the quickest way to get tbere. A sailor did it this past winter to SF without self steering
. He hove to at night and was on a very small boat so he spent several months making the passage
You should be able to find many accounts of the trip in 'Lattitude 38' magazine if you search their archives