I'm hoping to work up to single-handed passage between Hong Kong and Manila. Definitely planning to avoid typhoon season. I'm figuring on averaging 3-4 knots in my 28ft deep-keeled traditional sloop. Conservatively, should be able to make it in 10 days.
An average speed of 3 to 4 knots over a longish offshorepassage is a very fast speed for a traditional 28 footer being single-handed unless you plan to motor whenever your sailing speeds drop below 3 or so knots. Depending on the actual conditions, you might do better but it seems like historically, most traditional cruisers averaged roughly 50% or less than their hullspeeds.
Over a three year cruise, we (double-handed) averaged 4 knots on a 30 foot fairly heavy sloop, sailing conservatively. Rarely used the engine. If you're going to be in an area with reasonably consistent winds, 100 miles a day should be no problem.
Don't use a big word when a diminutive
one will suffice.
100 mile days in a 30 foot traditional boat is covering a fair amount of ground. One thing that helps your averages is that you are double-handing which allows sail changes to be made on the fly with one person steering. This means that you are more likely to carry a little more sail than a single-hander who has a lot more trouble shortening down when things get dicey.