Having recently done the Inside Passage
and spent last winter in Petersburg, AK, I'll pop in my 2 cents.
The selection of sailboats available in Alaska is very small. Agree with most on here that the vast majority of boats for sale
up there are power boats. Much better selection in the area from Portland
to lower BC (think Vancouver
/ Nanaimo area).
There is time to get up and back in one season. You will need to limit yourself as to what you want to see though. There are enough different cruising areas between Sitka and Seattle to keep you going for like 10 to 20 years. Beautiful spots abound.
You need (at least we did) a boat that has some sort of a good cover over some of the cockpit
area. It rains. A lot. Unless you want to stand in the rain while traveling on the boat a large part of the time; a good bimini/canvas enclosure is a very valuable thing to have on your boat. Alternatively - you can go for a pilothouse type. We met several people who owned Nauticats up in Alaska and were very pleased with them.
Lastly you need a boat with a decent engine
. Sailing up the Inside Passage is a little bit of a misnomer. We probably motored 80% to 85% of the time. Especially if you want to get up to SE Alaska, you will be going directly against the wind
in many passages. You can sail quite a bit; but you may not get as far as you would like to go or see all that you would like to.
and stern ties are common.