To answer your questions for the trip south from San Francisco to Channel Islands Harbor at Oxnard, CA.
Going north is a much rougher trip. Lots more miles & lots of harbors with a Bar that can not be entered if weather is bad. I will discuss that trip north another day.
So to go south from San Francisco, Plan for 4 to 5 days food, water & fuel to do this passage since your stopping each night.- may not need it - but better to have extra than not enough.
If you go straight through running 24 hours a day non-stop, figure about 2 day & 3 hours or about 51 hours will do it fine.
3 - danger areas - :
1. - Departing SF Bay & adjacent shipping lanes
2. - lea short of section from Monterey to San Simeon or Morro Bay, &
3. - going south of Port San Luis when headed in to area off Point Arguello & around Point Conception.
1. - You will not be able to go as fast as you think you will. You are not on flat water of SF Bay or the protected waters of the Santa Barbara Channel. Your in the real Pacific Ocean, so hope for the best but plan for the worst. We all want to go 8 knots - but the seas usually don't allow that. You need comfort for the long trip & you will have different shifts of people at the helm. Most of the time your running on Auto Pilot. So try to run at 7.0 to 7.5 knots & go from there. Usual average is 6.5 knots - of course weather dependent.
2. - Don't arrive at a strange port after sundown ! -- Always plan ahead with a buffer. So Look at the number of day light hours available to plan your departure time - this time of year maybe 15 hours of reliable daylight - so I looked up the sun tables for you - this coming weekend dawn is at 4:39 am & sun rise is at 5:43 am. Sunset is 8:00 pm & full dark is at 9:00pm.
So leave early at first dawn light & try hard to arrive before sunset. This is a safety thing.
Longest run is the Approximately 110 miles from Monterey to San Simeon Bay. That is a lea shore with NO WHERE to hide - so always confirm the weather before departure & monitor it enroute. Do not make the mistake of you running to close to the shore, Because if you clog a filter or such you need time & the farther your off shore the more time you have. I run 5 miles off minimum.
Figure average speed of 6.5 knots. Estimate Fuel burn of 2 to 3 an hour for small engine up to 4 to 5 gal per hour per engine - all speed dependent. Depends on how you run your engine, gearing, prop, engine size, How many engines, etc. You will be safe with those numbers. Every wave is a mountain you have to climb, so figure accordingly. They can be pretty big in this area.
Depends where your departing from inside San Francisco can make a big difference in 1st days progress as well as the tidal flow in the bay can effect your speed over the bottom a lot, -- as it can be a good part of the whole 1st day just getting to the Golden Gate depending where your departing from, timing, tides, weather, etc....
Next consideration is that some times weather & swells mean you can't take the south channel after mile rock & that means it would then require you to go all the way out to the sea buoy before you can turn south. Always, Stay in the channels as lots of sneaker waves in this area.
Also when you are in the process of leaving the SF Bay the tide timing is crucial as currents can be coming in as strong as 6 knots if the tide is against you & that can make for very slow going.
Also wind & currents that are adverse can make square waves that can beat you up till you get to deep water if the wind is strong & the tide is going out, so plan well for that. I prefer just before slack time by about 1 hour for under the GG When headed west. I prefer to go out to at least 5 miles off coast unless very, very calm & then you can maybe take south channel.
If there is any question - DO NOT TAKE SOUTH CHANNEL unless in very calm conditions - they get sneaker waves there that can roll your boat if taken on the beam.
If time & tides are not in your favor, to give your crew a rest make first day an easy one & head for Pillar Point Harbor at Half Moon Bay as back up to first stopping point for a comfortable over night sleep & rest for all. There are good restaurants there. My favorite is the "Ketch Joanne" . However, as you approach, Don't hug the coast as that is where "Mavericks'" is located with the world famous 30 foot swells.
SF to Half Moon Bay - as 1st possibility of first day progress - or if tides, wind, weather & sea condition allow then head for Monterey or Moss landing - 1st day. Skip Santa Cruz if you can as it is often shoaled in at entrance & can be tricky.
Second day is the jump from Monterey to San Simeon Bay or Morro Bay. or Port San Luis as back up to the back up.
I prefer San Simeon Bay as a planning point when winds are north west as some time they close the entrance to Morro Bay as there is a dangerous bar there & it can be impossible to get in. They are close to each other so if weather & seas allow you can do either one., but you have San Simeon in your hip pocket just in case - unless there is a south wind & swell - in which case stay away.
Third Day is San Simeon Bay or Morro Bay or Port San Luis headed out & then south -- around past Point Arguello & Point Conception -- which is the cape horn of the central California coast -- & then on down & into the Santa Barbara Channel. Stay well off shore in this Point Arguello & Conception area, -- do not hug the coast. Cape effect winds & seas in this area. There are several off shore oil rig's in the area, so use your radar.
After you round the cape & it's 2 points & get into the channel you can go into near by Cojo Anchorage or even go to Santa Barbara harbor - 35 miles. Great food in Santa Barbara. No facilities of any kind at Cojo, but good anchorage.
However, by then you may be smelling the barn & may want to head straight for Channel Islands Harbor. it is about 64 miles or so which at 8 knots is 8 hours. So You can now travel at 8 knots in the Santa Barbara Channel & make better time.
From there it is a easy run to Channel Islands Harbor at 64 miles.
best case 3 days with 2 over nights.
Average case 4 day with 3 over nights.
Worst case 5 days with 4 over nights
Approximately 325 Nautical Miles plus miles for going out & back to your off shore cruising route which adds about 10 additional miles a day.
Of course possible additional days lay over here or there if weather changes on you enroute.
NOTE: When you enter Channel Islands use the south of the break water entrance as the north end shoals in quickly after dredging.
Good luck & smooth seas.